As fraturas em equinos são responsáveis por grande prejuízo financeiro devido às dificuldades encontradas para instituir seu tratamento nessa espécie, principalmente em animais adultos. Entre as dificuldades técnicas no tratamento de fraturas em equinos estão a alta resistência óssea, que acarreta fraturas com grande transmissão de energia, e a escassez de materiais e técnicas de osteossíntese específicos para a espécie, gerando mau prognóstico em muitos casos. Estas fraturas, quando cominutivas acarretam em falhas ósseas, criando um espaço entre os fragmentos de maior tamanho e ainda extensa lesão de tecidos adjacentes, o que dificulta e prolonga o tempo de consolidação óssea. Atualmente a terapia com células tronco vem sendo bastante estudada em ortopedia, contudo o ambiente onde essas células são depositadas determina o caminho para onde elas vão se diferenciar. Para a utilização de células tronco em ortopedia, estas devem sem implantadas junto a um suporte tridimensional, por exemplo os biopolímeros, que além de fornecer um meio para a multiplicação e diferenciação dessas células, também deve apresentar características biomecânicas semelhantes ao tecido a ser reparado, que no caso da ortopedia é o tecido ósseo. O objetivo desse estudo foi avaliar as propriedades biomecânicas de dois biopolímeros a poliuretana de mamona com carbonato de cálcio e uma formulação de quitosana com fosfato de cálcio. Foram preparadas duas formulações diferentes de cada biopolímero, em corpos de prova cilíndricos de 12 mm de comprimento e 6 mm de diâmetro, sendo: poliuretana de mamona porosa e compacta, e quitosana com secagem a 38 e 60 graus Celsius. Essas formulações foram submetidas a ensaios compressivos nos momentos 3, 24, 48 e 72 horas após o preparo e avaliadas quanto sua resistência à compressão, deformação relativa e módulo de elasticidade. A poliuretana de mamona compacta apresentou o maior valor de resistência à compressão (45,805 N/mm2) após 48 horas. A fórmula de quitosana com secagem a 38oC apresentou a menor deformação relativa (3,952 %) após 72 horas de preparo e o maior valor de módulo de elasticidade encontrado foi na poliuretana de mamona compacta após 72 horas (1354,284 N/mm2). Sendo assim a poliuretana de mamona compacta apresenta maior resistência à compressão do que o osso esponjoso de terceiro metacarpiano equino e semelhante aos substitutos ósseos comerciais mais resistentes. A fórmula de quitosana 38oC apresentou valores similares aos observados no osso esponjoso equino. Podemos concluir com esses dados que a poliuretana de mamona compacta e a fórmula de quitosana 38oC apresentam características biomecânicas desejáveis nos materiais para enxerto ósseo. / Equine fractures are responsible for great economic losses due to difficulties in establishing their treatment, mainly regarding adult animals. Among technical difficulties faced in the equine fractures treatment, there are high bone strenght, which results in high energy fractures and the lack of materials and specific osteosynthesis techniques for the specimen, resulting bad prognostic in many cases. When cominutives, these fractures result in bone gaps, creating spaces between bigger fragments and still extensive surrounding tissue damages, which difficults and extends time for bone consolidation. Nowadays, therapy with steam cells is focused in orthopedy, but environment where these cells are established determines the path they will take. For the use of steam cells in orthopedy, they must be implanted together with a tridimensional support such as biopolymers which, besides offering conditions for replication and differentiation of these cells, they must present biomechanic characteristics similar to the tissue to be healed, which is the bone. The target of this study was to evaluate biomechanic properties of two biopolymers, a castor oil polyurethane with calcium carbonate and a formulation of chitosan with calcium phosphate. Two different formulations of each biopolymer were prepared, in cilindric parts of 12mm lenght and 6mm diameter: porous and compact castor oil polyurethane, and chitosan drying at 38oC and 60oC. These formulations were submitted to compressed tests at 3, 24 and 72 hours after preparation and evaluated for compressive strenght, relative deformation and modulus of elasticity. The compact castor oil polyurethane presented greater compressive value (45,805 N/mm2) after 48 hours. Chitosan formulation drying at 38oC presented lower relative deformation (3,952%) 72 hours after prepared, and the highest value for modulus of elasticity found was compact castor oil polyurethane after 72 hours (1354,284 N/mm2). Thus, compact castor oil polyurethane presents higher compressive strenght than trabecular bone of the third equine metacarpal and similar to strenghter comercial bone grafts. The formulation chitosan 38oC presented similar values to those observed in equine trabecular bone. With these data, we can conclude that the compact castor oil polyurethane and the formulation of chitosan 38oC present desirable biomechanic characteristics in materials for bone grafts.

Tese de mestrado integrado. Engenharia Civil. Faculdade de Engenharia. Universidade do Porto. 2010

The profile of the poloidal velocity in the edge region of tokamak plasmas has been identified as playing a major role in the confinement of particles and energy. It has been suggested that a strongly sheared poloidal flow can reduce particle and energy losses by the stabilization of unstable modes and decorrelation of turbulence the edge region of the plasma. A Gundestrup probe, a Mach probe array, is used to measure both the parallel and perpendicular flow velocities in the Saskatchewan Torus-Modified (STOR-M) tokamak during several discharge conditions. It is observed that during Ohmic discharges there is no velocity shear and the direction of the parallel flow is independent of the direction of the toroidal magnetic field. During H-mode induced by a turbulent heating current pulse, a region of strong velocity shear develops in the plasma edge and an edge transport barrier develops. This results in a short period of improved particle and energy confinement with reduced fluctuation amplitudes. During electrode biasing experiments, a stainless steel biasing electrode is inserted into the plasma up to r = 82 mm and biased to +500 V relative to the vacuum chamber. It is observed that the particle confinement improves during the biasing phase while the energy confinement is degraded. A region of weak shear in the poloidal flow is observed in the plasma scrapeoff layer (SOL). The results from STOR-M are compared with results from data taken in the Czech Academy of Sciences Torus (CASTOR) tokamak during both Ohmic discharges and discharges with electrode biasing.

Daugiau, kaip 80 % hidrografinio tinklo Lietuvoje sudaro melioracijos kanalai. Daugiau kaip 30 % bebrų populiacijos gyvena šiuose kanaluose. Bebrų veikla neretai trikdo normalų melioracijos sistemų funkcionavimą. Tyrimui pasirinktos dviejuose skirtinguose kraštovaizdžiuose esančios bebravietės (Molėtų bei Panevėžio rajonuose). Šiame darbe buvo tiriama bebraviečių tankumas, pasiskirstymas, erdvinės charakteristikos bei statybinės veiklos intensyvumas melioracijos kanaluose. Nustatytas bebrų poveikio mastas bei šio masto pokyčiai. Ištirtose teritorijose bebrų veikiama pusė melioracijos kanalų linijinio ilgio. Per 10 metų (1995-2005) bebraviečių skaičius melioracijos kanaluose praktiškai nepakito, taigi nekito ir melioracijos sistemoms daromas poveikis. / More than 80 % of hydro-graphical network in Lithuania is composed of drainage channels. More than 30 % of beaver populations in Lithuania live in drainage channels. Beaver activity often dislocates irrigations systems. This research was taken in two different landscapes. Beaver sites were visited in Moletai and Panevezys districts. Density, spread, dimensions and constructional activity were recorded in drainage channels. Also this study shows influence over the environment of changing number in beaver populations. Half of linear lengths of irrigation systems are influenced by beaver activity. The number of beaver sites did not change in a ten year period (1995-2005) as well as did not change the damage caused by beaver activity.

During seed development, myo-inositol (Ins) hexakisphosphate or phytic acid (PA) is stored in the form of phytin with mineral cations, and is mobilized following germination, releasing these nutrients that are required for seedling growth. Outside its role in seeds, PA and other phosphoylated Ins derivatives play critical roles in biological processes in many eukaryotes. PA also has negative influences on nutrition in both non-ruminant animals and humans due to its lack of digestibility. There have been two parallel PA biosynthetic pathways proposed, yet, the pathway is still poorly understood in terms of its regulation and enzymes involved. Here, genes encoding enzymes putatively implicated in castor bean PA biosynthetic pathways were identified in the genome and expression followed. Isolated castor bean embryos have the ability to resynthesize PA following germination if exogenous phosphate is available. It was found that the genes purported to act in PA synthesis were constitutively expressed in the embryos regardless of the availability of phosphate. Castor bean Ins 1,3,4,5,6-pentakisphosphate 2-kinase (RcIPK1), catalyzing the final reaction in PA biosynthesis, regardless of pathway, was chosen for further study. Even though only one copy of the RcIPK1 gene was present in the genome, numerous RNA variants were found, most likely due to alternative splicing events. These variants encoded six closely related protein isoforms based on in silico analysis. Functional analyses using yeast mutant strains lacking the IPK1 gene revealed that only three of the mRNA variants could rescue the temperature-sensitive growth phenotype, and it was demonstrated by HPLC analysis of Ins phosphates that their ability to complement the missing yeast IPK1 enzyme was associated with enzyme activity. Only these three isoforms possessed conserved motif III and motif IV important for IPK1 catalytic activity.

Abstract Plant cells contain plastids, organelles dedicated to performing specific biochemical processes including photosynthesis, starch and oil biosynthesis. Fatty acid biosynthesis in oil seeds occurs in one type of plastid termed the leucoplast. Anabolic metabolism in leucoplasts includes the production of fatty acids and amino acids that depend on the availability of reductants such as NADPH. NADPH can be generated in plastid by glucose 6-phosphate dehydrogenase (G6PDH) which is the chief control enzyme and first step in the Oxidative Pentose Phosphate Pathway (OPPP). G6PDH catalyses the reaction of NADP+ and glucose 6-phosphate to NADPH and 6-phosphogluconate. At least two compartment-specific isoforms of G6PDH exist in plants, a cytosolic and a plastidic form. In this study, castor oil seed (COS) (Ricinus communis L.) was used as a model enzyme system for the ongoing study of oil biosynthesis in plants. This is the first ever report of the full-length clone of the plastidic isoform of G6PDH being isolated from a castor cDNA library using polyclonal potato plastidic G6PDH antiserum. The full-length cDNA was sequenced and compared to other G6PDH genes from higher plants, the castor sequence reveals conserved regions and conserved cysteine residues similar to other higher plant G6PDH. Over expression of the recombinant cleaved fusion protein in an E. coli expression system from the isolation of the cDNA clone shows it is enzymatically active, stable and unlike other plastid G6PDH’s dithiothreitol insensitive. In fact this G6PDH shows increased activation in the presence of dithiothreitol. Initial kinetic characteristics shows that it behaves in a similar fashion enzymatically when compared to other higher plant chloroplast G6PDH. The gene sequence and initial kinetic findings for castor G6PDH concur with other higher plant, non-photosynthetic, plastidic isoforms. / Thesis (Master, Biology) -- Queen's University, 2007-09-19 13:41:54.584

Darbo tikslas. Parinkti tinkamą nevandeninį tirpiklį propolio ekstrakcijai bei ekstrakcijos sąlygas; įvertinti propolio fenolinių junginių atpalaidavimą iš skystų modelinių sistemų biofarmaciniu tyrimu in vitro. Darbo uždaviniai. Parinkti nevandeninius propolio ekstrahentus bei įvertinti jų gebą ekstrahuoti polifenolinius propolio junginius. Nustatyti ekstraktų kokybę lemiančius fizikocheminius rodiklius. Parinkti technologinius parametrus ir ištirti jų įtaką propolio ekstraktų kokybei. Įvertinti ekstraktų su propoliu stabilumą. Atlikti biofarmacinį tyrimą in vitro, siekiant nustatyti propolio fenolinių junginių atpalaidavimą iš skystos modelinės sistemos su tiriamuoju propolio ekstraktu (PE). Tyrimo metodai. Ekstraktai gaminti maceracijos metodu, bendras polifenolinių junginių kiekis (BFK) pagal kumaro rūgšties ekvivalentą (KRE) nustatytas ultravioletiniu (UV) spektrofotometru, taikant Folin-Ciocalteu metodą. Propolio ekstraktuose esančių polifenolinių junginių kiekio atpalaidavimas iš modelinių sistemų vykdytas in vitro metodu naudojant modifikuotas Franc tipo difuzines celes [4]. Rezultatai ir išvados. Tyrimo metu propolio ekstrakcijai parinkti trys nevandeniniai tirpikliai - izopropilo miristatas (IPM arba I), ricinos aliejus (R), etanolis, bei sistemos, sudarytos iš ricinos aliejaus ir izopropilo miristato, sumaišytų masės dalimis – 25R:75I, 50R:50I ir 75R:25I. Nustatytas tiesioginis ryšys tarp propolio koncentracijos ištraukose bei BFK naudojant skirtingus... [toliau žr. visą tekstą] / The aim of the study is to find out the most appropriate non-aqueous solvent and conditions for the propolis extraction; evaluate how propolis phenolic compounds release from the liquid model systems during the biopharmaceutical research called in vitro. The task of the study is to evaluate the ability of non-aqueous propolis extractions to extract poly-phenolic propolis compounds. Then find out physic-chemical characteristics which determine the quality of extracts. Next examine how selected technological parameters influence the quality of propolis extracts and evaluate the stability of propolis extracts. Conduct the biopharmaceutical research in vitro to determine the release of propolis phenolic compounds with propolis extract (PE) as an object of the study from the liquid model systems. Research methods. Extracts were produced using the maceration method. The ultraviolet (UV) spectrophotometer and Folin - Ciocalteu method were used to get the total quantity of poly-phenolic compounds (TFK) in accordance to the coumaric acid equivalent (KAE). The release of polyphenol compounds from the model systems in propolis extracts was carried out by in vitro method with modified Franc -type diffusion cells [4]. Results and Findings. The study of propolis extraction included three non-aqueous solvents, such as isopropyl myristate, castor oil and ethanol), as well as, systems made up with castor oil and isopropyl myristate, mixed in such ratios: 25R:75I , 50R:50I and 75R:25I. The... [to full text]

There has been a considerable effort in the last years to decrease the amount of volatile organic compounds (VOCs) present in organic coatings. The risks to human health and environmental hazards associated with VOCs, governmental directives, and economic factors are the main driving forces behind this effort. One way of achieving less or no VOC containing coating systems is to produce low viscosity resins. Hyperbranched resins owing to their globular structure have low viscosities and are promising materials for decreasing the VOCs. In this research hyperbranched resins having properties close to alkyds were synthesized. Dipentaerythritol, which was used as the core was esterified with dimethylol propionic acid. The hyperbranched polyester was then esterified with the castor oil fatty acids (Castor FA). The hydroxyl group of the ricinoleic acid present in the castor FA was modified with different amounts of linseed oil fatty acids (Linseed FA) and benzoic acid. The chemical characterization of the resins was achieved by FTIR spectroscopy and the thermal properties were determined by DSC. Then, the physical and the mechanical tests were carried out. The resins containing the Castor FA only and 32.5 % Linseed FA in addition to the Castor FA had 24 and 68 Persoz hardness, respectively. The viscosity of the resins decreased from 17.3 Pa&amp / #61655 / s to 5.8 Pa&amp / #61655 / s as the amount of the Linseed FA was increased. The resins showed excellent adhesion, gloss, flexibility and formability.

In this research hyperbranched resins containing fatty acid residues like alkyds were synthesized. Dipentaerythritol which has six hydroxyl groups was used as the core molecule, and it was transesterified with (i) castor oil, and (ii) a mixture of castor oil and linseed oil at 240&deg / C in the presence of sodium hydroxide as catalyst. The resulting molecule, in either case, was then esterified with dimethylol propionic acid at 140&deg / C in the presence of p-toluene sulfonic acid as catalyst. Melamine-formaldehyde resin was synthesized to be used with the synthesized hyperbranched resins, and it was successfully modified by all hyperbranched resins at a ratio of 3:1. FTIR spectroscopy was used to characterize the hyperbranched resins and the thermal properties were determined by DSC. DSC showed that the hyperbranched resins decomposed between 315-345&deg / C. The viscosity of the resin that was synthesized by using only castor oil was 3.0 Pa.s and by using 50% linseed oil it was 1.0 Pa.s. When reacted with dimethylol propionic acid, the former&rsquo / s viscosity increased to 7.0 Pa.s, and the second&rsquo / s viscosity increased to 3.7 Pa.s. The hyperbranched resins showed excellent adhesion, gloss, flexibility, and formability. The mixture of hyperbranched resin plus melamine-formaldehyde resin samples had higher hardness values but lower gloss, adhesion and bending resistance values than the hyperbranched resins, and they had good impact and abrasion resistances.

Orientador: Maurício Dutra Zanotto / Banca: Norberto da Silva / Banca: José Geraldo Carvalho do Amaral / Abstract: The castor bean (Ricinus communis L.) is high social economic value oil plant and a resource source to Brazil. To attend the increasing necessity of the raw material and the difficulty of production in industrial scale, it is essential the genetic material development in adequate size to facilitate the harvest, with precocious and uniform maturation, purposing the utilization of high technology and becoming possible the oil plant production in higher scale. The objective of this work was to evaluate the recurrent selection efficiency for height’s reduction of the castor bean plants Guarani cultivar, adequating its size to facilitate the harvest. Were developed four cycles of recurrent selection through the utilization of self-pollinated progenies in the Guarani cultivar for height’s reduction of plants, in edaphclimatic condictions of the São Manuel-SP and Botucatu-SP cities. The evaluations of plant’s height and grain’s productivity (kg.ha-1) of the four selection cycles and of the original cycle (cycle 0) were realized at São Manuel-SP and Botucatu-SP cities, under a casualised blocks design with five repetitions and useful parcels of 30 m2. The variance’s analysis for the characteristics plant’s height and grain’s productivity was made apart to each place and together for the two places and, afterwards it was realized the comparison of the averages by the Tukey test using 5% of probability. Were estimated for the two places, by the regression’s analysis... (Complete abstract click electronic access below) / Mestre