966 resultados para High weight molecular polyethylene
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Scientific and technological advancements in the area of fibrous and textile materials have greatly enhanced their application potential in several high-end technical and industrial sectors including construction, transportation, medical, sports, aerospace engineering, electronics and so on. Excellent performance accompanied by light-weight, mechanical flexibility, tailor-ability, design flexibility, easy fabrication and relatively lower cost are the driving forces towards wide applications of these materials. Cost-effective fabrication of various advanced and functional materials for structural parts, medical devices, sensors, energy harvesting devices, capacitors, batteries, and many others has been possible using fibrous and textile materials. Structural membranes are one of the innovative applications of textile structures and these novel building skins are becoming very popular due to flexible design aesthetics, durability, lightweight and cost benefits. Current demand on high performance and multi-functional materials in structural applications has motivated to go beyond the basic textile structures used for structural membranes and to use innovative textile materials. Structural membranes with self-cleaning, thermoregulation and energy harvesting capability (using solar cells) are examples of such recently developed multi-functional membranes. Besides these, there exist enormous opportunities to develop wide varieties of multi-functional membranes using functional textile materials. Additionally, it is also possible to further enhance the performance and functionalities of structural membranes using advanced fibrous architectures such as 2D, 3D, hybrid, multi-layer and so on. In this context, the present paper gives an overview of various advanced and functional fibrous and textile materials which have enormous application potential in structural membranes.
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This study focuses on the optimization of cheese whey formulated media for the production of hyaluronic acid HA by Streptococcus zooepidemicus. Culture media containing whey (W; 2.1 g/L) or whey hydrolysate (WH; 2.4 g/L) gave the highest HA productions. Both W and WH produced high yields on protein consumed, suggesting cheese whey is a good nitrogen source for S. zooepidemicus production of HA. Polysaccharide concentrations of 4.0 g/L and 3.2 g/L were produced in W and WH in a further scale-up to 5 L bioreactors, confirming the suitability of the low-cost nitrogen source. Cheese whey culture media provided high molecular weight (> 3000 kDa) HA products. This study revealed replacing the commercial peptone by the low-cost alternative could reduce HA production costs by up to a 70%compared to synthetic media.
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Dissertação de mestrado integrado em Engenharia Biomédica (área de especialização em Engenharia Clínica)
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Dissertação de mestrado em Biologia Molecular, Biotecnologia e Bioempreendedorismo em Plantas
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Enzymatic polymerization of aniline was first performed in lignosulfonate (LGS) template system. High-redox-potential catalyst laccase, isolated from Aspergillus, was used as a biocatalyst in the synthesis of conducting polyaniline/lignosulfonate (PANI-ES-LGS) complex using atmospheric oxygen as the oxidizing agent. The linear templates (LGS), also serving as the dopants, could facilitate the directional alignment of the monomer and improve the solubility of the conducting polymer. The process of the polymerization was monitored using UV-Vis spectroscopy, by which the conditions for laccase-catalyzed synthesis of PANI-ES-LGS complex were also optimized. The structure characterizations and solubility of the complex were carried out using corresponding characterization techniques respectively. The PANI-ES-LGS suspensions obtained was used as coating for cotton with a conventional padder to explore the applications of the complex. The variable optoelectronic properties of the coated cotton were confirmed by cyclic voltammetry and color strength test. The molecular weight changes of LGS treated by laccase were also studied to discuss the mechanism of laccase catalyzed aniline polymerization in LGS template system.
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Tese de Doutoramento em Biologia Molecular e Ambiental (área de especialização em Biologia Celular e Saúde).
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Tese de Doutoramento em Ciências (área de especialização em Química)
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OBJECTIVE: To determine if abnormal laboratory findings are more common in individuals with hypertension and in those with other risk factors, such as obesity, smoking and alcohol ingestion. METHODS: A study was carried out in the general outpatient clinics of a university hospital (145 individuals without previous diagnosis of hypertension) and the following variables were assessed: high blood pressure (as defined by the VI Joint National Committee on Prevention, Detection and Treatment of High Blood Pressure - VI JNC), obesity [calculated using body mass index (BMI)], tobacco use, and alcoholic ingestion. The laboratory examinations consisted of the following tests: hemogram, glycemia, uric acid, potassium, total/HDL-fraction cholesterol, triglycerides, calcium and creatinine. RESULTS: High blood pressure was not associated with a higher number of abnormal laboratory tests. Hypertensive individuals with a BMI > or = 25kg/m² or normotensive obese individuals, however, had a higher frequency of diabetes (12X), hypertriglyceridemia (3X), and hypercholesterolemia (2X), as compared with hypertensive individuals with BMI <25kg/m² and preobese/normal weight normotensive individuals. CONCLUSION: High blood pressure is not associated with a higher frequency of abnormal laboratory tests. The association of high blood pressure and obesity, however, increases the detection of diabetes and dyslipidemias.
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Genome-scale metabolic models are valuable tools in the metabolic engineering process, based on the ability of these models to integrate diverse sources of data to produce global predictions of organism behavior. At the most basic level, these models require only a genome sequence to construct, and once built, they may be used to predict essential genes, culture conditions, pathway utilization, and the modifications required to enhance a desired organism behavior. In this chapter, we address two key challenges associated with the reconstruction of metabolic models: (a) leveraging existing knowledge of microbiology, biochemistry, and available omics data to produce the best possible model; and (b) applying available tools and data to automate the reconstruction process. We consider these challenges as we progress through the model reconstruction process, beginning with genome assembly, and culminating in the integration of constraints to capture the impact of transcriptional regulation. We divide the reconstruction process into ten distinct steps: (1) genome assembly from sequenced reads; (2) automated structural and functional annotation; (3) phylogenetic tree-based curation of genome annotations; (4) assembly and standardization of biochemistry database; (5) genome-scale metabolic reconstruction; (6) generation of core metabolic model; (7) generation of biomass composition reaction; (8) completion of draft metabolic model; (9) curation of metabolic model; and (10) integration of regulatory constraints. Each of these ten steps is documented in detail.
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OBJECTIVE: To evaluate the level of satisfaction with body weight and the self-perception of the weight/height ratio and to verify the influence of the frequency of present and past physical activity on these variables. METHODS: Using questionnaires or interviews, we obtained height data, reported and desired weight, self-perception of the weight/height ratio, and the frequency of current physical activity in 844 adults (489 women). Of these, evaluated the frequency of physical activity during high school of 193 individuals,and we measured their height and weight. RESULTS: Less than 2/3 of the individuals had body mass index between 20 and 24.9 kg/m2. A tendency existed to overestimate height by less than 1 cm and to underestimate weight by less than 1kg. Desired weight was less than that reported (p<0.001), and only 20% were satisfied with their current weight. Only 42% of men and 25% of women exercised regularly. No association was found between the frequency of physical activity and the variables height, weight, and body mass index, and the level of satisfaction with current weight. CONCLUSION: Height and weight reported seem to be valid for epidemological studies, and great dissatisfaction with body weight and a distorted self-perception of height/weight ratio exists, especially in women, regardless of the frequency of physical activity.
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La provincia de Córdoba cuenta con alto desarrollo agrícola a base de cereales y leguminosas, como por ejemplo el maní. Pero este cultivo con los años ha trasladado su zona de siembra original y se ha extendido hacia otras áreas de mayor riesgo ambiental a raíz de la implantación de la soja. Diversas son las consecuencias de estas dos acciones y que se extienden desde lo agroecológico hasta lo científico-técnico. Este previo estado del arte y las referencias bibliográficas que apuntan a la necesitad de aumentar el valor agregado de los cultivos, nos ha llevado a formular una hipótesis de trabajo y es que las plantas de maní y soja así como las rizobacterias que se asocian con ellas, son productoras de diversas moléculas con potencial uso biológico en la productividad del cultivo y en aplicaciones tecnológicas, biológicas e industriales. Sumado a lo anterior y a las ideas gubernamentales de la necesidad de obtener conocimiento y capitalizarlo como riqueza, y la imperiosa urgencia de responder a demandas regionales, se presenta este proyecto cuyo objetivo general apunta a estudiar la producción de diversas moléculas de rizobacterias y leguminosas con el fin de mejorar la productividad de los cultivos y desarrollar nuevas aplicaciones tecnológicas en la provincia de Córdoba. Para cumplir dentro de los dos años de trabajo solicitados con lo expuesto anteriormente, la investigación será dividida en objetivos específicos y que consisten en investigar la producción de moléculas de raíces de maní y soja, analizar la respuesta microbiana a las rizodeposiciones de ambas leguminosas y evaluar el posible papel biológico y aplicación tecnológica de moléculas de ambos tipos de organismos. Nuestro grupo es de caracter multidisciplinar y ahondará en la diversidad molecular producida por raíces de maní y soja en direfentes días y la respuesta de las rizobacterias que se asocian ellas utilizando técnicas químicas (HPLC, GC, GC-masa) y herramientas microbiológicas y bioquímicas clásicas. Con fines de aplicación tecnológica se determinará la posible acción antioxidante de los extractos vegetales sobre sistemas modelos de ensayo así como la búsqueda de enzimas y hormonas microbianas aplicables en otros campos de la ciencia. De esta forma se pretende atender algunas demandas de diferentes sectores del centro sur de Córdoba y del país pero fundamentalmente posibilitar nuevas aplicaciones de las leguminosas y de las rizobacterias además de permitir la formación académicas de alumnos de grado y posgrado de la UNRC. The province of Cordoba has high agricultural development based on cereals and legumes such as peanuts. But the crop over the years has transferred his original planting area and has spread to other areas of greatest environmental risk following the introduction of soybeans. The previous state and regional art references that point to the necessity of increasing the value-added crops, has led us to formulate a working hypothesis is that the peanut and soybean plants and rhizobacteria associated with they are products of various biological molecules with potential use in crop productivity and biological technology and industrial applications. The general objective is aimed at studying the production of various molecules and legumes rhizobacteria to improve crop productivity and develop new technological applications in the Cordoba province. This form is intended to meet some demands of different sectors of the center south of Cordoba and the country but enabling new applications of legumes and rhizobacteria in addition to allowing the academic training of undergraduates and graduate of the UNRC.
Molecular phylogenies, chromosomes and dispersion in Brazilian akodontines (Rodentia, Sigmodontinae)
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A new molecular phylogeny for akodontine rodents from Brazil was proposed. The phylogenetic tree was enriched with the area of occurrence and with information on the karyotype of the samples. Based on this enriched tree, and with a described methodology, hypotheses were proposed on the karyotype and area of occurrence of the ancestors of each Clade. Thus it was possible to discuss hypotheses on chromosome evolution of the group, and on dispersion events from the "area of original differentiation" of akodontines in the Andes. Chromosome evolution started with high diploid numbers (2n=52) and showed a tendency to reduction (until 2n=14 in more recent clades). Independent side-branches of the tree showed 2n reduction and in one case the 2n increased. At least four dispersion events from the Andes down to South-eastern Brazil were proposed. The results should suggest the direction of new studies on comparative karyology.
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OBJECTIVE: The study tests the hypothesis that a low daily fat intake may induce a negative fat balance and impair catch-up growth in stunted children between 3 and 9y of age. DESIGN: Randomized case-control study. SETTING: Three rural villages of the West Kiang District, The Gambia. SUBJECTS: Three groups of 30 stunted but not wasted children (height for age z-score < or = -2.0, weight for height z-score > or = -2.0) 3-9 y of age were selected by anthropometric survey. Groups were matched for age, sex, village, degree of stunting and season. INTERVENTION: Two groups were randomly assigned to be supplemented five days a week for one year with either a high fat (n = 29) or a high carbohydrate biscuit (n = 30) each containing approximately 1600 kJ. The third group was a non supplemented control group (n = 29). Growth, nutritional status, dietary intake, resting energy expenditure and morbidity were compared. RESULTS: Neither the high fat nor the high carbohydrate supplement had an effect on weight or height gain. The high fat supplement did slightly increase adipose tissue mass. There was no effect of supplementation on resting energy expenditure or morbidity. In addition, the annual growth rate was not associated with a morbidity score. CONCLUSIONS: Results show that neither a high fat nor a high carbohydrate supplement given during 12 months to stunted Gambian children induced catch-up growth. The authors suggest that an adverse effect of the environment on catch-up growth persists despite the nutritional interventions.
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BACKGROUND: This study describes the prevalence, associated anomalies, and demographic characteristics of cases of multiple congenital anomalies (MCA) in 19 population-based European registries (EUROCAT) covering 959,446 births in 2004 and 2010. METHODS: EUROCAT implemented a computer algorithm for classification of congenital anomaly cases followed by manual review of potential MCA cases by geneticists. MCA cases are defined as cases with two or more major anomalies of different organ systems, excluding sequences, chromosomal and monogenic syndromes. RESULTS: The combination of an epidemiological and clinical approach for classification of cases has improved the quality and accuracy of the MCA data. Total prevalence of MCA cases was 15.8 per 10,000 births. Fetal deaths and termination of pregnancy were significantly more frequent in MCA cases compared with isolated cases (p < 0.001) and MCA cases were more frequently prenatally diagnosed (p < 0.001). Live born infants with MCA were more often born preterm (p < 0.01) and with birth weight < 2500 grams (p < 0.01). Respiratory and ear, face, and neck anomalies were the most likely to occur with other anomalies (34% and 32%) and congenital heart defects and limb anomalies were the least likely to occur with other anomalies (13%) (p < 0.01). However, due to their high prevalence, congenital heart defects were present in half of all MCA cases. Among males with MCA, the frequency of genital anomalies was significantly greater than the frequency of genital anomalies among females with MCA (p < 0.001). CONCLUSION: Although rare, MCA cases are an important public health issue, because of their severity. The EUROCAT database of MCA cases will allow future investigation on the epidemiology of these conditions and related clinical and diagnostic problems.
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In spite of the availability of multiple effector mechanisms of the immune system to combat tumour growth and metastases, their impairment frequently accompanies the appearance of cancer. Factors contributing to this impairment may be related to properties of the host and/or the tumour itself and may be with respect to their origin -endogenous or exogenour. Based on the unique biological behavior of prostate cancer (PCa), and its apparent escape from immune surveillance in the presence of tumour immuno genicity, continuing investigation of endogenous and exogenous factors thought to be relevant to its pathogenesis have been made. For this purpose further studies of the suggested role of human seminal plasma (SePl) and the synthetic oestrogen, diethylstiboestrol (DES), as representative endogenous and exogenous immunomodulatory factors (IMF) of tumour-host responsiveness, together with evaluation of human prostatic tissue extracts and leuprolide (the luteinizing-hormone-releasing-hormone proposed as an alternate to DES therapy) have been made by evaluating their effect on the lytic activity of natural killer (NK) cells. SePl and prostate extracts significantly suppressed NK cell lysis. Physicochemical studies suggest SePl and prostate IMF to be associated with high and low molecular weight macromolecules; and implicate the participation of transglutaminase and prostaglandins. Comparative study of therapeutic levels of DES vs. leuprolide on NK cell lysis demonstrated significant suppression by DES vs. a negligible effect of leuprolide. Metastases are highly prevalent in PCa, and contribute significantly to its morbidity and mortality. Further knowledge of the range of effects of endogenous and exogenous IMF on effector mechanisms of tumour-host responsiveness, to include suppression of NK cells, and elucidation of their nature, may contribute toward our understanding of the unique biological behavior of tumours of the prostate, in addition to improvement in their clinical management.