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despite the high social and economic importance of Spondias tuberosa Arruda, to the best of our knowledge there are very few detailed studies on the volatile compounds of this fruit popularly named umbu. Therefore, the aim of this study was to find the best extraction conditions by solid-phase microextraction in headspace mode (HS-SPME) to determine the volatile compounds from umbu fruit pulp by gas-chromatography coupled to mass spectrometry (GC-MS). The optimal conditions were obtained using 4 g of pulp and 0.2 NaCl/pulp (w/w), maintained for 10 min in incubation at 40 °C. The SPME-fiber was exposed for 20 min for extraction and then for 40 min for desorption. Thus, a total of 25 volatile compounds were detected and 16 were identified under these conditions, with 9 compounds being identified for the first time in the volatile fraction of umbu fruit pulp and two compounds were identified for the first time in the Spondias genus. The major chemical class was terpenes and esters, which together represent more than 90% of total chromatographic area. Resumo Apesar da alta importância social da Spondias tuberosa Arruda, têm sido raros os estudos sobre as substâncias voláteis de frutos do umbuzeiro conhecido como umbu. Por isso, o objetivo deste estudo foi determinar as melhores condições de extração destas substâncias por microextração em fase-sólida no modo headspace (MEFS-HS) para caracterizar o perfil de voláteis na polpa dos frutos de umbu por cromatografia gasosa acoplada à espectrometria de massas (CC-EM). As condições ótimas de extração foram obtidas usando 4 g da polpa da fruta e 0,2 NaCl/polpa (m/m), mantidos por 10 min em incubação a 40 °C. A fibra de MEFS foi exposta por 20 min para a extração dos compostos e, em seguida, por 40 min para dessorção no injetor do cromatógrafo. Nestas condições, um total de 25 substâncias voláteis foram detectadas, sendo 11 delas identificadas pela primeira vez na fração volátil de polpa de umbu e 3 compostos pela primeira vez no gênero Spondias. As principais classes químicas foram os terpenos e os ésteres, os quais, juntos, representam mais de 90 % da área cromatográfica total.

The chemical composition of volatile compounds from Spondias tuberosa fruits were investigated at four days of maturity and from two accessions. These days were characterized through the compounds’ profiles obtained by extracting volatiles using solid-phase microextraction in headspace mode (HS-SPME) and analyzed by gas-chromatography coupled to mass spectrometry (GC-MS). A total of 27 and 22 compounds were identified from the EPAMIG-C02 and EPAMIG-C10 accessions, respectively. The main chemical class in both accessions were the esters, aldehyde, alcohols and terpenes. The study revealed a tendency to increase the ester content and decrease the aldehyde and terpene content during four days of post-harvest ripening for the two accessions. This behavior may be monitored by five key compounds such as two esters (ethyl butanoate and ethyl hexanoate) and three aldehydes (hex-2-enal, nonanal and dec-2-enal). These compounds may be used as markers for the maturity stage for the two accessions. The Principal Components Analysis (PCA) accumulated 73.85% of the total variance in principal components 1 and 2 and showed that it is possible to differentiate the fruit ripening stages through these compounds.

In this study, the volatile organic compounds from Spondias tuberosa fruits of 16 accessions with different origins were extracted by solid-phase microextraction in headspace mode (HS-SPME) and analyzed by gas-chromatography coupled to mass spectrometry (GC-MS). The volatile compounds present in the fruit from the 16 accessions were identified and submitted to multivariate analysis, with the main volatile compounds identified (from a total of 25) being: ethyl butanoate, α-pinene, myrcene/ethyl caproate, limonene, ocimene isomers, linalool/nonanal and p-menth-1-en-4-ol. The major chemical classes were terpenes (about 7-72%) and esters (about 14-72%). The relative chromatographic areas of the volatile compounds were used in Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA), which accumulated 67.69% of the explained variance. The compounds classified as esters and terpenes were the main compounds responsible for forming distinct groups. The PC1 and PC2 enabled distinguishing the percentage of compounds responsible for grouping in the PCA quadrants and the HCA shows the grouping of these compounds.

Hyperbilirubinemia is a systemic global problem and an often diagnosed pathology in newborns. In most cases, blue-light phototherapy (410–460 nm) is the only treatment required to prevent the bilirubin neurotoxicity, but its effectiveness is dose-dependent and is highly affected by the skills, knowledge, and attention of nurses and clinicians who implement the treatment. This paper presents a novel light-sensitive colorimetric dosimeter to simulate the effect of blue-light phototherapy on the optical properties of in vitro bilirubin. The dosimeter is based on a multilayered organic structure comprising a light-stable green-light emitter (copper phthalocyanine, C 32 Cl 16 CuN 8 ), and a blue-light-sensitive red emitter (poly{[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene]vinylene}, OC 1O C 6 -PPV). The optical and chemical properties of the dosimeter were investigated by fluorescence and FTIR spectroscopies and by color coordinates of CIE (1931) diagram chromatics, while the photochemical processing of bilirubin was evaluated by UV–vis absorption spectroscopy. The optical response of the dosimeter under conventional (10 μW/cm 2 ) and intensive (40 μW/cm 2 ) phototherapy was found to present the same photochemical kinetics as bilirubin. These findings highlight a cutting-edge solution for monitoring bilirubin elimination in neonates as a function of the dosimeter’s color evolution. This novel colorimetric dosimeter provides a standardized method of reporting and measuring phototherapy dose to promote an efficient use of available phototherapy units in health facilities.

Neste trabalho as propriedades ópticas do poli[2-metóxi,5-(2’etil-hexiloxi)-p-fenilenovinileno] - MEH-PPV foram estudadas sob efeito de luz azul proveniente de super LEDs utilizada no tratamento da hiperbilirrubinemia neonatal (ou icterícia). Os resultados mostraram que o MEH-PPV apresenta uma mudança de cor do vermelho-alaranjado para o incolor, passando por diversas tonalidades de amarelo, bem como uma diminuição da intensidade dos espectros de absorção e de fotoluminescência (PL) em função do tempo de exposição à radiação. Essas mudanças foram usadas para projetar um sensor de acúmulo de dose de radiação azul, tipo indicador de cores, para avaliar a dose de radiação recebida por recém-nascidos durante o tratamento da icterícia neonatal. In this work we investigated the optical behavior of poly[2-methoxy-5(2’-ethylhexyloxy)-p-phenylenevinylene] (MEH-PPV) under the effect of blue-light LED source applied in neonatal hyperbilirubinemia treatment. There is a visible response that covers the electronic absorption of bilirubin (350-500 nm), and hence this material is applicable for controlling the radiation doses in the treatment of jaundice of neonates, which is one of the most common reasons for hospital readmission of newborn infants. The results show that the material presents a gradation of color from orange-red to yellow and quenching on the absorption and photoluminescent (PL) spectra with the radiation exposure time. The rate of these changes can be altered by manipulations of organic solution concentration, suggesting these color and emission/absorption changes can be used to design an indicator-dosimeter that is readily associated with the radiation exposure time used in treating neonatal jaundice.

The central process of neonatal phototherapy by employing blue light has been attributed to the configurational conversion of (4Z,15Z)-bilirubin to (4Z,15E). Indeed, photoisomerization is the early photochemical event during this procedure. However, in this paper, we show that the bilirubin solutions under continuous blue light exposure undergo a photooxidation process. To ascertain the role of this photodegradation in the phototherapy, we evaluated UV–visible absorption spectra obtained from bilirubin solutions in CHCl3, milli-Q water, and physiological saline, as well as FTIR spectroscopy for bilirubin in CHCl3. These analyses also showed that the first 2 h of phototherapy are the most relevant period. In addition, quantum molecular modeling using B3LYP/6-31G(d,p) and ZINDO/S-CIS was performed to evaluate the electronic and structural properties of four bilirubin isomers, showing that the (4Z,15E)-bilirubin isomer is the most polar configuration. Therefore, it can be more soluble in aqueous environments than the other configurations. This clarifies why this is the faster isomer excreted during the phototherapy.

This article presents a novel radiochromic film for selective detection of low-medium (0–10 kGy) gamma radiation (60Co) doses. This dosimeter is based on a printed fluorescent multilayer structure comprising a paper substrate having layers of copper phthalocyanine (DY220) (a green emitter material) on the bottom, and layers of poly[2-methoxy-5(2′-ethylhexyloxy)-p-phenylenevinylene] (MEH-PPV) (a green-light absorber, red emitter, and radiation sensitive polymer) on the top. The effect of gamma radiation on the optical properties of DY220/MEH-PPV was described: it was observed as a strong correlation between radiation dose and fluorescent, color coordinates for CIE (1931) chromatic diagram, and Pantone color reference of the dosimeter. The rate of these changes can be altered by manipulation of top–bottom layers to represent easily the radiation dose to be determined in a wide range. This versatile dosimeter has many uses in the field of food radiation for monitoring, quality assurance, and control of the gamma radiation process. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45729.

Optical absorption and fluorescence measurements have been done on poly[2-methoxy-5-(2′-ethyl-hexyloxy)-1,4-phenylene vinylene]/[aluminum-tris(8-hydroxyquinoline)] solutions. The authors show that there is a visible response that covers the electronic absorption of bilirubin ( 350 – 500 nm ) , and hence, this material is applicable for managing the radiation doses planning before treatment of jaundice of neonates, which is one of the most common reasons of hospital readmission of newborns infants. The results show that the material presents a gradation of color from orange to yellow clearly, while its peak position emission shifts from orange-red ( λ max = 571 nm ) to green ( λ max = 540 nm ) with the radiation exposure time. The rate of these changes can be altered by manipulations of organic solution concentration and they are usually slow (from 2 to 8 h ), suggesting these color and emission changes can be used to design an easy to make, easy to read, easy to operate, low cost ( US $0.50) and accuracy for individual monitoring indicator dosimeter in order to represent easily the radiation exposure time usually used in management of neonatal jaundice.

The control of the photo degradation of a fluorene–vinylene–phenylene based-polymer, poly(9,9-di-hexylfluorenediylvinylene- alt -1,4-phenylenevinylene) (LaPPS16) was achieved by addition of a radical scavenger (RS) (enhancing photo resistance) or a radical initiator (RI) (reducing photo resistance). Photoluminescence, UV–Vis absorption, 1 H NMR spectroscopies and gel permeation chromatography (GPC) revealed that the incorporating small amounts of RS or RI is an efficient way to control the rates of the photo-oxidation reactions, and thus to obtain the conjugated polymer with foreseeable degradation rates for applications in blue-light sensitive detectors for neonatal phototherapy.

In this paper, we report our experimental design in searching a smart and easy-to-read dosimeter used to detect 6MV X-rays for improving patient safety in radiation oncology. The device was based on an organic emissive solutions of poly(2-methoxy-5(2′-ethylhexyloxy)- p -phenylenevinylene) (MEH-PPV), aluminum-tris-(8-hydroxyquinoline) (Alq 3 ) and additive components which were characterized by UV–Vis absorption, photoluminescence and CIE color coordinate diagram. The optical properties of MEH-PPV/Alq 3 solutions have been examined as function of radiation dose over the range of 0–100Gy. It has shown that MEH-PPV/Alq 3 solutions are specifically sensitive to X-rays, since the effect of radiation on this organic system is strongly correlated with the efficient spectral overlap between Alq 3 emission and the absorption of degraded MEH-PPV, which alters the color and photoemission of MEH-PPV/Alq 3 mixtures from red to yellow, and then to green. The rate of this change is more sensitive when MEH-PPV/Alq 3 is irradiated in the presence of benzoyl peroxide than when in the presence of hindered phenolic stabilizers, respectively, an accelerator and an inhibitor to activate or inhibit free radical formation. This gives rise to optimize the response curve of the dosimeter. It is clear from the experimental results that organic emissive semiconductors have potential to be used as dedicated and low-cost dosimeters to provide an independent check of beam output of a linear accelerator and therefore to give patients the opportunity to have information on the dose prescription or equipment-related problems a few minutes before being exposed to radiation.

Neste trabalho são apresentadas a fabricação e a caracterização óptica de um novo detector de raios X para monitoramento da dose nos processos de radioterapia empregando fótons de alta energia (6,0 MV). O dispositivo foi fabricado a partir de materiais orgânicos luminescentes consolidados como elemento ativo de displays eletroluminescentes nanoestrurados, mas que, até esse momento, têm sido pouco investigados como detectores de radiação ionizante. Para tanto, foram preparadas soluções à base de tris(8-hidroxiquinolato) de alumínio - Alq3 e poli(2-metóxi-5-(2-etilhexiloxi)-pfenilenovinileno) – MEH-PPV, cujo espectro de emissão do primeiro material se sobrepõe ao de absorção do segundo. Os resultados obtidos mostram que os espectros de emissão do sistema MEH-PPV/Alq3 desloca-se do vermelho-laranja (λmax = 598 nm) para o verde (λmax = 545 nm) quando a dose de radiação vai de 0 a 100 Gy. Essa mudança, consequência da degradação induzida pela radiação do MEH-PPV, foi usada no desenvolvimento de dosímetros para possível futura aplicação no controle do tratamento de pacientes oncológicos. In this work it is presented the characterization and fabrication of a novel ionizing radiation detector for high energy photon beam (6.0 MV). It is used organic luminescent materials usually applied in light-emitting and nanostructure device, but still few explored in radiation dosimetry. Organic solutions of tris(8-hydroxyquinolinato) aluminum - Alq3 and poly[2-methoxy-5-(2’-ethylhexyloxy)-p-phenylene vinylene] - MEH-PPV were prepared to better study the impact of spectral overlap between the Alq3 emission and MEH-PPV absorption. It is observed a blue-shift on the photoluminescence of the MEH-PPV/Alq3 solution system from red-orange (λmax = 598 nm) to green (λmax = 545 nm) when the radiation dose changes from 0 to 100 Gy. This effect is attributed to the photoxidation process of MEH-PPV and was employed to design dose accumulation detector in order to represent easily the radiation dose for cancer treatment.

We report on the design, fabrication and performance of a poly (2-methoxy-5(2_-ethylhexyloxy)- p-phenylenevinylene)/tris-(8-hydroxyquinoline)aluminum (MEH-PPV/Alq3) X-ray dose detector for improving safety for cancer patients shortly before radiation therapy. The detector consists of an inexpen-sive (

A fototerapia com luz azul (460 nm - 490 nm) é o procedimento mais utilizado para o tratamento da icterícia em recém-nascidos. Contudo, dois fatores alteraram drasticamente a eficiência desse tratamento: (1) o espectro da fonte luminosa e (2) a dose de radiação absorvida pelos neonatos. Este trabalho apresenta o desenvolvimento de detectores de radiação orgânicos e flexíveis, de baixo custo, de bom desempenho e de fácil operação para monitoramento da radiação incidente em neonatos ictéricos sob tratamento fototerápico. O princípio de funcionamento dos dispositivos baseia-se na resposta óptica de filmes finos à base de dois materiais orgânicos luminescentes: o tris (8-hidroxiquinolinato de alumínio) - Alq3 e o poli[2-metóxi-5-(2’-etilóxi)-p-fenilenovinileno] - MEH-PPV, dispersos em matriz de poliestireno – PS sob efeito de luz azul. Os resultados obtidos mostram que a radiação atua no sentido de alterar a intensidade de máxima emissão do vermelho ao verde, passando pelo amarelo, dos filmes de PS/MEH-PPV/Alq3. Esse resultado é atribuído à fotodegradação do MEH-PPV e, consequentemente, as mudanças na sobreposição entre os espectros de emissão do Alq3 e de absorção desse polímero. A resposta óptica dos filmes com a radiação foi usada para fabricar um sensor orgânico flexível, inédito e de custo inferior a R$ 0,50, para controle das condições de exposição de neonatos ictéricos à fototerapia com luz azul. Blue-light therapy (460 nm - 490 nm) is the most common treatment of jaundice in newborns. However, the efficiency of this treatment is dependent of two factors: (1) the spectrum of light source and (2) the delivered dose to the neonates. This work presents the development of a low-cost, flexible, good performance and an easy detector operation based on organic materials for evaluation of radiation dose delivered by the phototherapy units to jaundice newborns. The operation principles of the device is based on the optical response of poly [2-methoxy-5-(2’-ethylhexyloxy)-p-phenylene - MEH-PPV, tris (8-hydroxyquinolinato aluminum)-Alq3 and polystyrene-PS thin films under the effects of blue-light. It is observed that the optical response of the PS/MEH-PPV/Alq3 films changes from red to yellow, and then to green with the radiation exposure. It is attributed to the photodegradation process of MEH-PPV and also to the spectral overlap between the photoemission of Alq3 and the absorption of MEH-PPV. The optical response of PS/MEH-PPV/Alq3 films was used to develop a novel organic flexible and low cost (

A hindered phenol type radical scavenger (Irganox 1010®) was used to improve the resistance to photo-oxidation in PPV-type polymers. The degradation was performed under blue light (460 nm), and the effect of the added compound was investigated following the intensity variation of absorbance and photoluminescence spectra. The results showed that the addition of the compound brought about a significant enhancement in photodegration resistance without interfering in the electronic properties of the polymers. These results suggest that the free radical scavenger attenuates the decrease of the polymer conjugation length induced by the radiation. FTIR measurements confirm this evidence.

The present work details, to our knowledge, the first examination of the influence of blue-light radiation on the optical properties of organic luminescent films in attempting to develop an indicator dosimeter for phototherapy of neonatal jaundice. Jaundice is the most common problem encountered in newborns due to immature functioning in the liver. The operating principle of the device is based on the optical response of poly[2-methoxy-5-(2'-ethylhexyloxy)-p-phenylene (MEH-PPV) and tris(8-hydroxyquinolinato) aluminum (Alq3) materials dispersed in polystyrene (PS) matrix (denoted as PS/MEH-PPV/Alq3). It is observed a blue-shift on the photoluminescence of PS/MEH-PPV/Alq3 system from red to orange-yellow, and then to green as function of the blue-light radiation exposure time. The result is attributed to the spectral overlap between emission of Alq3 and absorption of MEH-PPV. The optical response of PS/MEH-PPV/Alq3 to radiation was investigated to design a low-cost (< US$ 0.05) “smart” sensor to represent easily the radiation dosage normally used in blue-light phototherapy. The basic idea behind this concept considers the sensor as a traffic light device, where red represents underdose and green the prescription dose or overdose, while orange-yellow suggests that radiation therapy is an ongoing process. This personal real-time radiation dosimeter appears here as a key requirement for successful development of innovations in effective management of the radiation dose planning before treatment of neonatal where control of dose absorption of infants is extremely important.

CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior O uso indiscriminado de produtos químicos tem contribuído para a contaminação de organismos e ecossistemas. Os herbicidas a base de glifosato são muito utilizados devido ao custo relativamente baixo e excelente eficiência na eliminação de plantas daninhas. Além de sua elevada eficácia, esse herbicida é classificado como pouco tóxico, sendo rapidamente convertido no seu principal metabólito, o Ácido Aminometilfosfônico (AMPA), embora estudos apontem possíveis efeitos deletérios para organismos e o ambiente. Nesse contexto, o objetivo deste trabalho foi otimizar e validar um método analítico para a determinação de glifosato e AMPA em amostras de águas, utilizando a extração em fase sólida e detecção por cromatografia líquida de alta eficiência acoplada ao espectômetro de massas por plasma indutivamente acoplado (ICP-MS/MS). Houve separação dos compostos com tempo total de análise inferior a 5 minutos. O método foi seletivo, não apresentando interferentes no tempo de retenção dos analitos e apresentou-se linear. Os limites de quantificação de 1,09 µg L-1 para o glifosato e 0,29 µg L-1 para o AMPA foram abaixo dos valores máximos de resíduos definidos pela resolução CONAMA Nº 430 para os cursos hídricos. O método foi preciso e exato, sendo obtida uma recuperação média de 99% ± 0,99 para o glifosato e 98% ± 5,41 para o AMPA, e não se apresentou efeito de matriz. O método foi aplicado em amostras de água de cultivo hidropônico de mudas de eucalipto, para verificar se ocorreu a exsudação. Os resultados mostraram que foi detectado glifosato nas amostras, revelando sensibilidade suficiente para detectar a exsudação do glifosato pelas raízes de eucalipto. Nessas amostras, o glifosato oriundo do processo de exsudação foi de 1,38 a 1,54 µg L-1 do analito na solução hidropônica. The indiscriminate use of chemicals has contributed to the contamination of organisms and ecosystems. Glyphosate-based herbicides are widely used due to their relatively low cost and excellent weeding efficiency. In addition to its high efficacy, this herbicide is classified as low toxic and rapidly converted to its main metabolite, Aminomethylphosphonic Acid (AMPA), although studies indicate possible deleterious effects on organisms and the environment. In this context, the objective of this work was to optimize and validate an analytical method for glyphosate and AMPA determination in water samples using solid phase extraction and detection by high performance liquid chromatography coupled to the inductively coupled plasma mass spectrometer (HPLC-ICP-MS/MS). Compounds were separated with a total analysis time of less than 5 minutes. The method was selective, not interfering with the retention time of the analytes and was linear. The limits of quantification of 1,09 µg L-1 for glyphosate and 0,29 µg L-1 for AMPA were below the maximum residue values defined by resolution CONAMA Nº 430 for the water courses. The method was precise and accurate, obtaining an average recovery of 99%± 0,99 for glyphosate and 98%± 5,41 for AMPA, and there was no matrix effect. The method was applied to water samples from hydroponic cultivation of eucalyptus seedlings, to verify if the exudation occurred. The results showed that glyphosate was detected in the samples, revealing sufficient sensitivity to detect glyphosate exudation by eucalyptus roots. In these samples, glyphosate from the exudation process was 1,38 to 1,54 µg L-1 of the analyte in the hydroponic solution.