Moisture and temperature dependence of the dielectric properties of pharmaceutical powders

The dielectric properties of pharmaceutical powder-(paracetamol, aspirin, lactose, maize starch, adipic acid) solvent (water) mixtures were measured at 2,450 MHz at a range of moisture contents (0-1.0 kg kg(-1), dry basis) and temperatures (20-70 A degrees C). The dielectric constant (epsilon'), loss factor (epsilon aEuro(3)) and penetration depth (d (p)) were found to be dependent on frequency, moisture content, temperature and powder type. For powder-water mixtures, a linear increase in the dielectric properties with moisture content was observed, whilst the temperature dependence was of quadratic form. The penetration depth was also significantly affected by temperature and moisture content. Although, epsilon aEuro(3) also increased with increasing temperature, variation with moisture content was temperature dependent. This information on dielectric properties is essential for mathematical description of the pharmaceutical product temperature history during microwave heating and for the design of microwave drying equipment.

Diabetic-like loss of corneal sensitivity in the 50% galactose fed rat is ameliorated with topical administration of an aldose reductase inhibitor

Purpose: To investigate the temporal course of corneal sensitivity loss & the role of aldose reductase inhibitors (ARI) in an animal model of diabetic ocular complications. Methods: Weanling male S-D rats were randomly grouped to received ad libitum water & diet consisting of Purina (#5001) w/ either: 50% starch (CON,n=15) or 50% D-galactose (GAL,n=30). Half the galactosemic rats (ARI,n=15) received topical 0.25% CT-112 (3x daily, 20µl, Senju Pharmaceutical Co., Japan). Control & remaining half of the galactosemic animals received equivalent doses of saline eyedrops. Rats were restrained w/o medication during sensitivity measurements conducted w/ a Cochet-Bonnet Aesthesiometer mounted on a micromanipulator. The end of the filament (0.012mm dia.), which applied a mean pressure of 0.96 g/mm perpendicular to the corneal surface at center, was in the plane of focus of a slit-lamp biomicroscope. Measurements were conducted by two investigators which were masked to the treatment group. The average blink-responses from 10 consecutive stimuli to each cornea were expressed as a percent. Results: Mean (±SD) baseline corneal sensitivity in all groups were similar (CON 73%±11, GAL 71%±15, ARI 74%±16). Corneal sensitivity in the galactosemic rat was decreased (p

Experimental investigation of thermoforming carbon fibre-reinforced polyphenylene sulphide composites

Pre-consolidated carbon fibre-reinforced polyphenylene sulphide (CF/PPS) laminates were
thermoformed into V-shaped parts via designed out of autoclave thermoforming experiments.
The different processing conditions tested in the experiment have resulted in final
part angles whose differences ranged from 2.087 to 3.431 from the original mould angle.
The test results show that processing conditions influenced finished part dimensions as the
final sample angles were found to decrease relative to the tooling dimensions, as mould
temperature increases. Higher mould temperature conditions produce thinner parts due
to the thermal expansion of mould tools. The mould temperature of 170C, which can
produce parts with high degree of crystallinity as well as small size of crystal, has been
established as the optimal thermoforming condition for CF/PPS composites.

Lactobacillus strains isolated from infant faeces possess potent inhibitory activity against intestinal alpha- and beta-glucosidases suggesting anti-diabetic potential

Purpose: Inhibitors of intestinal alpha-glucosidases are used therapeutically to treat type 2 diabetes mellitus. Bacteria such as Actinoplanes sp. naturally produce potent alpha-glucosidase inhibitor compounds, including the most widely available drug acarbose. It is not known whether lactic acid bacteria (LAB) colonising the human gut possess inhibitory potential against glucosidases. Hence, the study was undertaken to screen LABs having inherent alpha- and beta-glucosidase inhibitory potential. Methods: This study isolated, screened, identified and extracted Lactobacillus strains (Lb1–15) from human infant faecal samples determining their inhibitory activity against intestinal maltase, sucrase, lactase and amylase. Lactobacillus reference strains (Ref1–7), a Gram positive control (Ctrl1) and two Gram negative controls (Ctrl2–3), were also analysed to compare activity. Results: Faecal isolates were identified by DNA sequencing, with the majority identified as unique strains of Lactobacillus plantarum. Some strains (L. plantarum, L. fermentum, L. casei and L. rhamnosus) had potent and broad spectrum inhibitory activities (up to 89 %; p < 0.001; 500 mg/ml wet weight) comparable to acarbose (up to 88 %; p < 0.001; 30 mg/ml). Inhibitory activity was concentration-dependent and was freely available in the supernatant, and was not present in other bacterial genera (Bifidobacterium bifidum and Escherichia coli or Salmonella typhimurium). Interestingly, the potency and spectrum of inhibitory activity across strains of a single species (L. plantarum) differed substantially. Some Lactobacillus extracts had broader spectrum activities than acarbose, effectively inhibiting beta-glucosidase activity (lactase) as well as alpha-glucosidase activities (maltase, sucrase and amylase). Anti-diabetic potential was indicated by the fact that oral gavage with a L. rhamnosus extract (1 g/kg) was able to reduce glucose excursions (Area under curve; 22 %; p < 0.05) in rats during a carbohydrate challenge (starch; 2 g/kg). Conclusion: These results definitively demonstrate that Lactobacillus strains present in the human gut have alpha- and beta-glucosidase inhibitory activities and can reduce blood glucose responses in vivo. Although the potential use of LAB such as Lactobacillus as a dietary supplement, medicinal food or biotherapeutic for diabetes is uncertain, such an approach might offer advantages over drug therapies in terms of broader spectrum activities and fewer unpleasant side effects. Further characterisation of this bioactivity is warranted, and chronic studies should be undertaken in appropriate animal models or diabetic subjects.

Effect of carbohydrate type and concentration on polyhydroxy alcohol and trehalose content of conidia of three entomopathogenic fungi

The entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae and Paecilomyces farinosus were cultured on solid agar media containing different carbohydrate components (glycerol, glucose, trehalose or starch) at concentrations of ≤ 142.7 g added carbon 1-1 for 30 d at 25°C. The water activity (a(w)) of the media ranged from 0.925 to 0.998. Growth of M. anisopliae and P. farinosus was stimulated between 0.975 and 0.995 a(w) on glucose media and that of P. farinosus at 0. 975 a(w) on glycerol media. At < 0.970 a(w), growth of each fungal species was significantly reduced (P < 0.05). Polyhydroxy alcohols (polyols) and trehalose were extracted from conidia produced on different media and quantified using HPLC. Total polyol content of conidia produced on glucose media varied between 5.2 and 52.2 mg g-1 for B. bassiana, 77.3 and 90.3 mg g-1 for M. anisopliae, and 26.7 and 76.1 mg g-1 for P. farinosus. The amounts of specific polyols in conidia varied significantly from media of different glucose concentrations. Mannitol was the predominant polyol in conidia of all three species, with conidia of M. anisopliae, for example, containing as much as 75.2 mg mannitol g-1 when cultured on glucose media. The amount of the lower molecular mass polyols glycerol and erythritol was greater in conidia produced on glucose media with > 50.0 g added carbon 1-1 than that in conidia produced at lower glucose concentrations. Conidia contained between 10.8 and 20.8 mg glycerol plus erythritol g-1 on glucose media with 142.7 g added carbon 1-1, depending on species. Conversely, conidia of B. bassiana and P. farinosus contained maximum amounts of trehalose ( ≤ 23.5 mg g-1) when produced on glucose media with < 50.0 g added carbon l-1, and trehalose content was considerably less at higher glucose concentrations. There were accumulations of glycerol and erythritol in conidia of all three species when grown on glycerol media with > 25.0 g added carbon 1-1; conidia of B. bassiana contained up to 154.0 mg glycerol plus erythritol g-1. hen B. bassiana and P. farinosus were grown on trehalose media, conidia contained up to 222.1 mg trehalose g-1. By contrast, conidia of M. anisopliae contained < 17.0 mg trehalose g-1 under all conditions tested. The water availability of solutions of different polyols is discussed in relation to their potential to act in osmotic adjustment during germination. The ability to manipulate polyol and trehalose content of fungal propagules may be critical in enhancing the storage life and efficacy of biological control agents.

Melt Processing and Properties of Polyamide 6/Graphene Nanoplatelet Composites

Graphene, due to its outstanding properties, has become the topic of much research activity in recent years. Much of that work has been on a laboratory scale however, if we are to introduce graphene into real product applications it is necessary to examine how the material behaves under industrial processing conditions. In this paper the melt processing of polyamide 6/graphene nanoplatelet composites via twin screw extrusion is investigated and structure–property relationships are examined for mechanical and electrical properties. Graphene nanoplatelets (GNPs) with two aspect ratios (700 and 1000) were used in order to examine the influence of particle dimensions on composite properties. It was found that the introduction of GNPs had a nucleating effect on polyamide 6 (PA6) crystallization and substantially increased crystallinity by up to 120% for a 20% loading in PA6. A small increase in crystallinity was observed when extruder screw speed increased from 50 rpm to 200 rpm which could be attributed to better dispersion and more nucleation sites for crystallization. A maximum enhancement of 412% in Young's modulus was achieved at 20 wt% loading of GNPs. This is the highest reported enhancement in modulus achieved to date for a melt mixed thermoplastic/GNPs composite. A further result of importance here is that the modulus continued to increase as the loading of GNPs increased even at 20 wt% loading and results are in excellent agreement with theoretical predictions for modulus enhancement. Electrical percolation was achieved between 10–15 wt% loading for both aspect ratios of GNPs with an increase in conductivity of approximately 6 orders of magnitude compared to the unfilled PA6.

The 'human revolution' in lowland tropical Southeast Asia:the antiquity and behavior of anatomically modern humans at Niah Cave (Sarawak, Borneo)

Recent research in Europe, Africa, and Southeast Asia suggests that we can no longer assume a direct and exclusive link between anatomically modern humans and behavioral modernity (the 'human revolution'), and assume that the presence of either one implies the presence of the other: discussions of the emergence of cultural complexity have to proceed with greater scrutiny of the evidence on a site-by-site basis to establish secure associations between the archaeology present there and the hominins who created it. This paper presents one such case study: Niah Cave in Sarawak on the island of Borneo, famous for the discovery in 1958 in the West Mouth of the Great Cave of a modern human skull, the 'Deep Skull,' controversially associated with radiocarbon dates of ca. 40,000 years before the present. A new chronostratigraphy has been developed through a re-investigation of the lithostratigraphy left by the earlier excavations, AMS-dating using three different comparative pre-treatments including ABOX of charcoal, and U-series using the Diffusion-Absorption model applied to fragments of bones from the Deep Skull itself. Stratigraphic reasons for earlier uncertainties about the antiquity of the skull are examined, and it is shown not to be an `intrusive' artifact. It was probably excavated from fluvial-pond-desiccation deposits that accumulated episodically in a shallow basin immediately behind the cave entrance lip, in a climate that ranged from times of comparative aridity with complete desiccation, to episodes of greater surface wetness, changes attributed to regional climatic fluctuations. Vegetation outside the cave varied significantly over time, including wet lowland forest, montane forest, savannah, and grassland. The new dates and the lithostratigraphy relate the Deep Skull to evidence of episodes of human activity that range in date from ca. 46,000 to ca. 34,000 years ago. Initial investigations of sediment scorching, pollen, palynomorphs, phytoliths, plant macrofossils, and starch grains recovered from existing exposures, and of vertebrates from the current and the earlier excavations, suggest that human foraging during these times was marked by habitat-tailored hunting technologies, the collection and processing of toxic plants for consumption, and, perhaps, the use of fire at some forest-edges. The Niah evidence demonstrates the sophisticated nature of the subsistence behavior developed by modern humans to exploit the tropical environments that they encountered in Southeast Asia, including rainforest. (c) 2006 Elsevier Ltd. All rights reserved.

Aspects of dietary carbohydrate intake are not related to risk of colorectal polyps in the Tennessee Colorectal Polyp Study

Purpose: High digestible carbohydrate intakes can induce hyperglycemia and hyperinsulinemia and collectively have been implicated in colorectal tumor development. Our aim was to explore the association between aspects of dietary carbohydrate intake and risk of colorectal adenomas and hyperplastic polyps in a large case–control study.

Methods: Colorectal polyp cases (n = 1,315 adenomas only, n = 566 hyperplastic polyps only and n = 394 both) and controls (n = 3,184) undergoing colonoscopy were recruited between 2003 and 2010 in Nashville, Tennessee, USA. Dietary intakes were estimated by a 108-item food frequency questionnaire. Unconditional logistic regression analysis was applied to determine odds ratios (OR) and corresponding 95 % confidence intervals (CI) for colorectal polyps according to dietary carbohydrate intakes, after adjustment for potential confounders.

Results: No significant associations were detected for risk of colorectal adenomas when comparing the highest versus lowest quartiles of intake for total sugars (OR 1.03; 95 % CI 0.84–1.26), starch (OR 1.01; 95 % CI 0.81–1.26), total or available carbohydrate intakes. Similar null associations were observed between dietary carbohydrate intakes and risk of hyperplastic polyps, or concurrent adenomas and hyperplastic polyps.

Conclusion: In this US population, digestible carbohydrate intakes were not associated with risk of colorectal polyps, suggesting that dietary carbohydrate does not have an etiological role in the early stages of colorectal carcinogenesis.

The determination of optimal processing conditions for PLA and PLA/CaCO3 in twin screw extrusion using DoE and multivariate analysis

Biodegradable polymers, such as PLA (Polylactide), come from renewable resources like corn starch and if disposed of correctly, degrade and become harmless to the ecosystem making them attractive alternatives to petroleum based polymers. PLA in particular is used in a variety of applications including medical devices, food packaging and waste disposal packaging. However, the industry faces challenges in melt processing of PLA due to its poor thermal stability which is influenced by processing temperatures and shearing.
Identification and control of suitable processing conditions is extremely challenging, usually relying on trial and error, and often sensitive to batch to batch variations. Off-line assessment in a lab environment can result in high scrap rates, long lead times and lengthy and expensive process development. Scrap rates are typically in the region of 25-30% for medical grade PLA costing between €2000-€5000/kg.
Additives are used to enhance material properties such as mechanical properties and may also have a therapeutic role in the case of bioresorbable medical devices, for example the release of calcium from orthopaedic implants such as fixation screws promotes healing. Additives can also reduce the costs involved as less of the polymer resin is required.
This study investigates the scope for monitoring, modelling and optimising processing conditions for twin screw extrusion of PLA and PLA w/calcium carbonate to achieve desired material properties. A DAQ system has been constructed to gather data from a bespoke measurement die comprising melt temperature; pressure drop along the length of the die; and UV-Vis spectral data which is shown to correlate to filler dispersion. Trials were carried out under a range of processing conditions using a Design of Experiments approach and samples were tested for mechanical properties, degradation rate and the release rate of calcium. Relationships between recorded process data and material characterisation results are explored.

Predicting impact damage, residual strength and crashworthiness of composite structures

The development of the latest generation of wide-body carbon-fibre composite passenger aircraft has heralded a new era in the utilisation of these materials. The premise of superior specific strength and stiffness, corrosion and fatigue resistance, is tempered by high development costs, slow production rates and lengthy and expensive certification programmes. Substantial effort is currently being directed towards the development of new modelling and simulation tools, at all levels of the development cycle, to mitigate these shortcomings. One of the primary challenges is to reduce the extent of physical testing, in the certification process, by adopting a ‘certification by simulation’ approach. In essence, this aspirational objective requires the ability to reliably predict the evolution and progression of damage in composites. The aerospace industry has been at the forefront of developing advanced composites modelling tools. As the automotive industry transitions towards the increased use of composites in mass-produced vehicles, similar challenges in the modelling of composites will need to be addressed, particularly in the reliable prediction of crashworthiness. While thermoset composites have dominated the aerospace industry, thermoplastics composites are likely to emerge as the preferred solution for meeting the high-volume production demands of passenger road vehicles. This keynote presentation will outline recent progress and current challenges in the development of finite-element-based predictive modelling tools for capturing impact damage, residual strength and energy absorption capacity of thermoset and thermoplastic composites for crashworthiness assessments.

Contribuição para a melhoria da qualidade nutricional do sorgo

Este trabalho teve como principal objectivo sugerir uma forma de processamento de sorgo adaptável à escala industrial que, sendo culturalmente aceite e sensível aos hábitos alimentares, aos factores sociais e às limitações económicas e tecnológicas das populações Africanas de consumo, pudesse dar origem a um produto alimentar seguro e enriquecido em termos nutricionais. Numa primeira fase, efectuou-se um estudo comparativo entre os efeitos promovidos por diferentes formas de processamento: cozimento em água, aquecimento em banho-maria, pipocagem, germinação, fermentação e altapressão. Foram ainda determinadas as condições óptimas de aplicação do processo germinativo e da tecnologia de alta-pressão. Verificou-se que a fermentação, a germinação e a alta-pressão permitem uma melhoria significativa da digestibilidade proteica da farinha de sorgo. A pipocagem conduziu a uma redução da extractibilidade das proteínas não promovendo, contudo, alterações na sua digestibilidade. Comparativamente ao cozimento em água, que promove uma diminuição acentuada na digestibilidade proteica, o cozimento em banho-maria promove uma diminuição ténue e significativamente inferior. Deste estudo comparativo, foi possível concluir que a extractibilidade das proteínas não está correlacionada com a sua digestibilidade e que a água exerce um papel fundamental na diminuição da digestibilidade proteica com o aquecimento. Numa segunda fase, pretendeu-se desenvolver um processo fermentativo que conduzisse a um produto de sorgo com características nutricionais incrementadas. Para tal, foram testadas daiferentes espécies de bactérias lácticas isoladas e conjugadas entre si. Foi ainda testada a adição de malte de sorgo previamente à fermentação e a adição de leveduras ao inóculo. Com este estudo, foi possível concluir que a fermentação do sorgo com um inóculo constituído por culturas puras de Lactobacillus brevis, Lactobacillus fermentum e Streptococcus thermophilus permite a obtenção de uma preparação alimentar com características nutricionais melhoradas no que respeita ao balanço em aminoácidos essenciais, à digestibilidade da proteína e do amido e à viscosidade do produto final.

Efeito da pressão e temperatura em suspensões de amido

O objetivo do presente trabalho consistiu no estudo das propriedades viscoelásticas de suspensões de amido nativo e processado a alta pressão. Foi utilizado um sensor acústico de forma a analisar as propriedades das suspensões, sendo depois recolhidas informações complementares através de outras técnicas: calorimetria diferencial de varrimento, microscopia de luz polarizada e microscopia eletrónica de varrimento. Neste trabalho foram realizados estudos com amido de milho nativo e processado a alta pressão (500 MPa, 5 minutos, temperatura ambiente), tendo-se verificado que a suspensão do amido processado apresentava propriedades viscoelásticas muito diferentes do amido nativo. A temperatura a que se iniciou o aumento da viscosidade foi mais elevada para o amido processado a alta pressão, e as variações observadas para temperaturas superiores a 70 °C foram menores. Durante o arrefecimento foi detetada uma diminuição da viscosidade, correspondente a um aumento da organização molecular, com maior expressão no amido nativo mas que se dá no mesmo intervalo de temperatura, quer para este quer o processado a alta pressão. Foi também possível concluir que a velocidade de aquecimento da amostra de amido influencia as propriedades viscoelásticas da suspensão e as temperaturas a que ocorrem as variações de viscosidade relacionadas com o processo de gelatinização do amido. De assinalar também que no amido de milho se pode detetar pela variação da frequência do cristal piezoelétrico o rompimento dos grânulos e que apesar do estabelecimento de novas ligações e da reposição de alguma ordem molecular que se pode verificar durante o arrefecimento, a frequência da suspensão depois de arrefecida era muito diferente da suspensão de amido inicial. No amido de arroz, a temperatura a que se inicia o aumento de viscosidade foi superior à que se observou para o amido de milho, indicio da maior resistência do amido de arroz, para o qual não se detetou sinal de rutura dos grânulos. A frequência final da suspensão do mesmo, depois de arrefecido, era igual à inicial. Com o amido de arroz foi feito o estudo da influência da temperatura no processamento de alta pressão, tendo sido processadas suspensões a 400 MPa, durante 15 minutos, a 5, 10, 23 e 34 °C. As propriedades viscoelásticas foram analisadas com recurso a um sensor acústico, tendo-se verificado que quanto maior a temperatura de processamento a alta pressão, mais elevada a temperatura necessária para que se inicie o aumento de viscosidade e menores as temperaturas a que se inicia diminuição da mesma durante o arrefecimento.

Propriedades intrínsecas e de processamento de termoplásticos elastoméricos incorporando borracha de pneu reciclada

O trabalho apresentado tem por objetivo contribuir para a valorização da borracha proveniente de pneus em fim de vida, assente em princípios de sustentabilidade ambiental. A abordagem adotada para a concretização deste objetivo consiste na incorporação de borracha de pneus em formulações de base termoplástica e elastomérica (TPE), adequadas ao processo de moldação por injeção. São desenvolvidos estudos sobre a morfologia, propriedades mecânicas, térmicas e reológicas das ligas poliméricas à base de granulado de borracha de pneu (GTR). A falta de adesão entre o GTR e a matriz polimérica leva à degradação das propriedades mecânicas dos materiais obtidos. A estratégia explorada passa pela utilização de um elastómero para promover o encapsulamento do GTR e, desta forma, procurar obter ligas com propriedades mecânicas características de um TPE. São analisadas ligas ternárias (TPEGTR) compostas por polipropileno (PP) de elevada fluidez, GTR e elastómero virgem. O efeito da presença de diferentes elastómeros nas ligas é analisado neste trabalho: um elastómero de etilenopropileno- dieno (EPDM), e um novo elastómero de etileno-propileno (EPR) obtido por catálise metalocénica. O estudo da morfologia das ligas obtidas mostra haver interação entre os materiais, sendo possível inferir a viabilidade da estratégia adotada para promover a adesão do GTR. A incorporação de elastómero promove o aumento da resistência ao impacto e da extensão na rotura nas ligas, o que é atribuído, fundamentalmente, ao encapsulamento do GTR e ao aumento da tenacidade da matriz termoplástica. Com o objetivo de avaliar a influência da estrutura cristalina das ligas TPEGTR no seu comportamento mecânico, procede-se à análise do processo de cristalização sob condições isotérmicas e não isotérmicas. Neste estudo, é avaliado o efeito da presença dos materiais que constituem a fase elastomérica na cinética de cristalização. Para cada uma das ligas desenvolvidas, recorre-se ao modelo de Avrami para avaliar o efeito da temperatura no mecanismo de nucleação, na morfologia das estruturas cristalinas e na taxa de cristalização. Recorre-se à reometria capilar para estudar, sob condições estacionárias, o comportamento reológico das ligas TPEGTR. O modelo de Cross-WLF é utilizado para avaliar o comportamento reológico de todos os materiais, obtendo-se resultados similares àqueles obtidos experimentalmente. O comportamento reológico dos polímeros PP, EPR e EPDM é do tipo reofluidificante, tendo o EPR um comportamento reológico similar ao do PP e o EPDM um comportamento reo-fluidificante mais pronunciado. Em todas as ligas analisadas o comportamento reológico revela-se do tipo reo-fluidificante, sendo que a presença de GTR promove o aumento da viscosidade. Os parâmetros obtidos do modelo de Cross-WLF são utilizados para realizar a simulação da etapa de injeção recorrendo a um software comercial. Os resultados obtidos são validados experimentalmente pelo processo de moldação por injeção, evidenciando uma boa adequabilidade da aplicação deste modelo a estas ligas. O trabalho desenvolvido sobre ligas TPEGTR, constitui um contributo para a valorização da borracha proveniente de pneus em fim de vida, assente em princípios de sustentabilidade ambiental.

Physiology and metabolic profile of Moringa olifera and Eucalyptus globulus plants subjected to climate changes

As alterações climáticas emergentes têm um grande impacto no crescimento e desenvolvimento de espécies florestais, nomeadamente em espécies de valor industrial e medicinal, como é o caso do eucalipto (Eucalyptus globulus) e da moringa (Moringa oleifera). Assim, é urgente conhecer as respostas fisiológicas e entender as variações que ocorrem nos perfis metabólicos de espécies vegetais. Neste trabalho, plantas jovens de Eucalyptus globulus foram expostas a radiação UVB (12kJ/m2) e foram avaliadas as respostas fisiológicas e o perfil metabólico, um e onze dias após a aplicação da radiação. A dose de UVB usada não afetou as reações fotoquímicas nem as trocas gasosas, contudo ao nível do metabolismo do carbono (AST e amido) e do conteúdo de pigmentos verificaram-se pequenas alterações (AST e pigmentos). Através da análise do perfil metabólico de E. globulus foram encontrados compostos voláteis e semi-voláteis pertencentes às famílias dos terpenos, sesquiterpenos e aldeídos. Em geral, os sesquiterpenos e os álcoois monoterpénicos apresentaram uma tendência para manter e, em alguns casos, diminuir com o stress, enquanto que o grupos dos aldeídos aumentou e os monoterpenos apresentaram um comportamento mais heterogéneo. O E. globulus mostrou ser uma espécie tolerante à aplicação da dose de UVB usada neste trabalho. Por outro lado, plantas jovens de M. oleifera foram expostas a défice hídrico (DH). Um grupo de plantas foi recolhido um dia após o final da exposição e o outro grupo após onze dias do final da exposição. Foi avaliado o perfil metabólico desta espécie através de GC/MS. Os dados cromatográficos indicaram que em condições de stress (DH(1) e DH(11)), as quantidades de compostos associados a vias primárias e secundárias de defesa (como os alcanos, álcoois, ácidos carboxílicos, esteróis, aminoácidos e açucares) sofreram algumas alterações. As plantas analisadas 11 dias após a remoção do stress mostraram maiores variações do perfil de metabolitos. No entanto, tanto um como onze dias após a remoção do stress, as plantas apresentaram a formação de novos rebentos. Apesar do perfil de metabolitos ter sofrido algumas alterações, por não se registarem casos de morte, conclui-se que as plantas de moringa mostraram ser tolerantes aos tratamentos aplicados.

Early nutritional programming in fish: tailoring the metabolic use of dietary carbohydrates

Tese de doutoramento, Ciências da Vida, do Mar, da Terra e do Ambiente (Nutrição), Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015