Approaches in biotechnological applications of natural polymers

Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

Computational performance and cross-validation error precision of five PLS algorithms using designed and real data sets

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)An evaluation of computational performance and precision regarding the cross-validation error of five partial least squares (PLS) algorithms (NIPALS, modified NIPALS, Kernel, SIMPLS and bidiagonal PLS), available and widely used in the literature, is presented. When dealing with large data sets, computational time is an important issue, mainly in cross-validation and variable selection. In the present paper, the PLS algorithms are compared in terms of the run time and the relative error in the precision obtained when performing leave-one-out cross-validation using simulated and real data sets. The simulated data sets were investigated through factorial and Latin square experimental designs. The evaluations were based on the number of rows, the number of columns and the number of latent variables. With respect to their performance, the results for both simulated and real data sets have shown that the differences in run time are statistically different. PIS bidiagonal is the fastest algorithm, followed by Kernel and SIMPLS. Regarding cross-validation error, all algorithms showed similar results. However, in some situations as, for example, when many latent variables were in question, discrepancies were observed, especially with respect to SIMPLS. Copyright (C) 2010 John Wiley & Sons, Ltd.2441795320332Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Sorting variables by using informative vectors as a strategy for feature selection in multivariate regression

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)A new procedure with high ability to enhance prediction of multivariate calibration models with a small number of interpretable variables is presented. The core of this methodology is to sort the variables from an informative vector, followed by a systematic investigation of PLS regression models with the aim of finding the most relevant set of variables by comparing the cross-validation parameters of the models obtained. In this work, seven main informative vectors i.e. regression vector, correlation vector, residual vector, variable influence on projection (VIP), net analyte signal (NAS), covariance procedures vector (CovProc), signal-to-noise ratios vector (StN) and their combinations were automated and tested with the main purpose of feature selection. Six data sets from different sources were employed to validate this methodology. They originated from: near-infrared (NIR) spectroscopy, Raman spectroscopy, gas chromatography (GC), fluorescence spectroscopy, quantitative structure-activity relationships (QSAR) and computer simulation. The results indicate that all vectors and their combinations were able to enhance prediction capability with respect to the full data sets. However, regression and NAS informative vectors from partial least squares (PLS) regression, both built using more latent variables than when building the model presented in most of tested data sets, were the best informative vectors for variable selection. In all the applications, the selected variables were quite effective and useful for interpretation. Copyright (C) 2008 John Wiley & Sons, Ltd.23416713248Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Hérnias diafragmáticas traumáticas: Revisão casuística Traumatic diaphragmatic hernias: Retrospective analysis

Objectivos: Os autores propuseram-se realizar uma revisão e caracterização dos casos de hérnias diafragmáticas (HD) traumáticas internados no Serviço de Medicina Intensiva dos Hospitais da Universidade de Coimbra (SMI-HUC) de 1990 a 2004. Material e métodos: Análise retrospectiva de 34 casos de HD traumática, tendo em atenção a localização anatómica, o local e o momento do diagnóstico, os exames complementares que permitiram o diagnóstico, os órgãos herniados, os traumatismos associados, a morbilidade e a mortalidade. Resultados: Vinte e oito doentes eram do sexo masculino e 6 do feminino, com média de idades de 40,2 ± 20,5 anos; o valor médio do SAPS foi de 38,8. A duração média de internamento foi de 19,1 ± 13,6 dias, todos sofreram traumatismo fechado e foram submetidos a ventilação artificial. A hérnia localizava-se à esquerda em 94,1% dos casos. O diagnóstico em 19 dos casos foi efectuado até 6 horas após o traumatismo, em 4 casos até às 12 horas, e os restantes entre 48 horas e 16 anos após o traumatismo. Em 13 doentes o diagnóstico foi intra-operatório. Dos órgãos herniados, o estômago estava presente na maioria da situações. As lesões associadas mais frequentes foram, a nível torácico, a contusão pulmonar, o hemotórax e o pneumotórax, e a nível abdominal o hemoperitoneu e a lesão esplénica. A taxa de complicações e de mortalidade foi 55,8 % e de 11,7 %, respectivamente. Conclusões: A HD ocorreu maioritariamente à esquerda por traumatismo toraco-abdominal fechado na sequência de acidente de viação. Este grupo de doentes, em relação aos valores médios do Serviço, era mais jovem, apresentava maior duração média de internamento, apresentando, no entanto, menores taxa de mortalidade e índice de gravidade (SAPS). O órgão herniado mais frequente foi o estômago, e as lesões associadas mais encontradas foram os traumatismos crânio-encefálico, esplénico e pleuro-costal. A dificuldade de diagnóstico pré-operatória continua a requerer elevado grau de suspeição, exigindo-se sempre a colocação desta hipótese de diagnóstico no contexto de traumatismos toraco-abdominais fechados.Aims: This study classifies cases of traumatic diaphragmatic hernias (TDH) in patients admitted to the Intensive Care Unit (ICU) of the Coimbra University Hospitals (HUC) from 1990 to 2004. Methods: Retrospective analysis of 34 cases of TDH, studying anatomical location, place and time of diagnosis, complementary tests aiding diagnosis, herniated organs, associated traumatism, morbidity and mortality. Results: Twenty-eight male and six female patients with an average age of 40.5 years ± 20.5, average SAPS score 38.8. Average lenght of stay was 19.1± 13.6 days, all suffered from closed traumatism and were put on artificial ventilation. The left-side diaphragm was more frequently affected (94.1%) then the right. Diagnosis in 19 cases was made up in the first six hours following the diagnosis of traumatism, in four cases within 12 hours and in the remaining cases between 48 hours and 16 years after traumatism. In 13 patients the diagnosis was established intra-operatively. The stomach was typically one of the herniated organs. The most frequently associated lesions at the thoracic level were pulmonary contusion, haemothorax and pneumothorax, and at the abdominal level, haemoperitoneum and splenic lesion. The rates for complications and mortality were 55.8% and 11.7% respectively. Conclusions: TDH mainly occurs on the left side through closed thoraco-abdominal trauma following road traffic accidents. This group of patients, on average younger than others admitted to ICU, presents a longer average hospitalisation period, but has lower rates of mortality and lower SAPS severity scores. The most commonly herniated organ was the stomach and the most frequently encountered lesions were cranial-encephalic, splenic and pleural traumatisms. Pre-operative diagnosis of diaphragmatic injuries is difficult and a high index of clinical suspicion is needed after thoraco-abdominal trauma. This diagnosis should always be considered a possibility in cases of closed thoraco-abdominal traumas

Multivariate QSAR study on the antimutagenic activity of flavonoids against 3-NFA on Salmonella typhimurium TA98

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)A quantitative structure activity relationship (QSAR) study of twenty flavonoid derivatives with antimutagenic activity against 3-nitrofluoranthene (3-NFA) was performed by Partial Least Squares (PLS), using Ordered Predictors Selection (OPS) algorithm for variable selection. Four descriptors (PJI2, Mor27m, G1e and R4u divided by) were selected and a good model (n = 19; R(2) = 0.747; SEC = 0.332, PRESS(cal) = 1.768, F((2.27)) = 23.585; Q(LOO)(2) = 0.590; SEV = 0.388; PRESS(val) = 2 858; R(pred)(2) = 0.591; SEP = 0.394; ARE(pred) = 5.230%, k = 1.005; k' = 0.990; vertical bar R(0)(2) -R(0)'(2)vertical bar = 0 109) was built with two latent variables describing 83 410% of the original information. Leave-N-out cross validation (LNO) and y-randomization were performed in order to confirm the robustness of the model The topological descriptors selected indicate that the antimutagenic activity against 3-NFA depends on molecular size, shape and Sanderson electronegativity of flavonoids. The proposed model may provide a better understanding of the antimutagenic activity of flavonoids and can be used as a guidance for proposition of new chemopreventive agents. (C) 2010 Elsevier Masson SAS All rights reserved.451045624569Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2004/04686-5

Physiological and physico-chemical characterization of dietary fibre from the green seaweed Ulva fasciata Delile

This work aims to assess the potential of the green seaweed Ulva fasciata Delile as an alternative source of dietary fibre (DF). Total DF content was determined, some of its physico-chemical properties described and the physiological effects of U. fasciata meal on rats fed a hypercholesterolemic diet were investigated. U. fasciata may be considered a potential alternative source of DF with a total content of about 400 g.kg-1 (dry basis) and interesting physico-chemical properties: water retention capacity of 8.74 g/water.g-1 dry sample (seaweed meal) and 0.90 (seaweed carbohydrate extract), lipid adsorption capacity of 4.52 g/oil.g-1 dry sample (seaweed meal) and 5.70 (seaweed carbohydrate extract), intrinsic viscosity of 2.4 dl.g-1 (seaweed carbohydrate extract) and cation exchange capacity of 3.51 Eq.kg-1 (seaweed carbohydrate extract). The diet containing seaweed meal was able to keep rats' total cholesterol (TC) down without causing any undesirable increase in LDL-C fraction. No evidence of toxic and/or antinutritional components in the seaweed meal was detected. Rats showed a fecal volume much greater (13 g) than that fed on cellulose diet ( 7 g) (p < 0.05). These properties confer on the seaweed the potential to be used in food technology for the acquisition of low-calorie food and might be important in body weight control, reduction of blood TC and LDL-C as well as in prevention of gastrointestinal diseases

Chronic Ethanol Consumption Alters All-Trans-Retinoic Acid Concentration and Expression of Their Receptors on the Prostate: A Possible Link Between Alcoholism and Prostate Damage

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Background Ethanol (EtOH) alters the all-trans-retinoic acid (ATRA) levels in some tissues. Retinol and ATRA are essential for cell proliferation, differentiation, and maintenance of prostate homeostasis. It has been suggested that disturbances in retinol/ATRA concentration as well as in the expression of retinoic acid receptors (RARs) contribute to benign prostate hyperplasia and prostate cancer. This study aimed to evaluate whether EtOH consumption is able to alter retinol and ATRA levels in the plasma and prostate tissue as well as the expression of RARs, cell proliferation, and apoptosis index. Methods All animals were divided into 4 groups (n = 10/group). UChA: rats fed 10% (v/v) EtOH ad libitum; UChACo: EtOH-naive rats without access to EtOH; UChB: rats fed 10% (v/v) EtOH ad libitum; UChBCo: EtOH-naive rats without access to EtOH. Animals were euthanized by decapitation after 60 days of EtOH consumption for high-performance liquid chromatography and light microscopy analysis. Results EtOH reduced plasma retinol concentration in both UChA and UChB groups, while the retinol concentration was not significantly different in prostate tissue. Conversely, plasma and prostate ATRA levels increased in UChB group compared with controls, beyond the up-regulation of RAR beta and -? in dorsal prostate lobe. Additionally, no alteration was found in cell proliferation and apoptosis index involving dorsal and lateral prostate lobe. Conclusions We conclude that EtOH alters the plasma retinol concentrations proportionally to the amount of EtOH consumed. Moreover, high EtOH consumption increases the concentration of ATRA in plasma/prostate tissue and especially induces the RAR beta and RAR? in the dorsal prostate lobe. EtOH consumption and increased ATRA levels were not associated with cell proliferation and apoptosis in the prostate.3714956Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES