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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Purifica??o e caracteriza??o estrutural de homogalactanas sulfatadas anticoagulantes da alga verde Codium isthmocladum

Sabry, Diego de Ara?jo 14 April 2010 (has links)
Made available in DSpace on 2015-03-03T14:00:59Z (GMT). No. of bitstreams: 1 DiegoAS_DISSERT.pdf: 1474988 bytes, checksum: 09ed96a182fab36b0c95800c391aded7 (MD5) Previous issue date: 2010-04-14 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Os polissacar?deos sulfatados comp?em um grupo complexo de macromol?culas com uma gama de importantes atividades biol?gicas, incluindo atividade antiviral, anticoagulante, antiproliferativa, antitumoral e antioxidante. Esses pol?meros ani?nicos s?o amplamente distribu?dos em tecidos de vertebrados e algas. As algas marinhas s?o as fontes, n?o-mam?feras, mais abundantes de polissacar?deos sulfatados na natureza. Os mais conhecidos extra?dos de algas vermelhas s?o homogalactanas, chamadas de carragenanas, e de algas marrons s?o homo ou heteropolissacar?deos, chamadas de fucanas e fucoidanas, respectivamente, e os polissacar?deos sulfatados de algas verdes s?o compostas por polissacar?deos contendo galactose, glicose, arabinose e/ou ?cido glucur?nico. H? poucos estudos descrevendo a presen?a de polissacar?deos sulfatados em algas verdes. No presente estudo, o extrato total de polissacar?deos da alga verde Codium isthmocladum foi obtido atrav?s de digest?o proteol?tica, e fracionado por precipita??o sequencial com acetona resultando em cinco fra??es (F0,3V; F0,5V; F0,7V; F0,9V e F1,2V). O teste de atividade anticoagulante de aPTT mostrou que F0,5V desempenhou alta atividade anticoagulante. Esta foi, posteriormente, fracionada por cromatografia de troca-i?nica em sete polissacar?deos: F0,3M; F0,5M; F0,7M; F1,0M; F1,5M; F2,0M e F3,0M. Os polissacar?deos elu?dos com F2,0M e F3,0M migraram como um ?nico componente eletrofor?tico. N?o foi detectada contamina??o prot?ica. An?lises qu?micas mostraram que F2,0M e F3,0M s?o compostas por galactose. Esses polissacar?deos foram submetidos ao teste de aPTT, e mostraram alta atividade anticoagulante com atividade maior que Clexane?. Ambas apresentaram um efeito dose-dependente. An?lises estruturais de F2,0M e F3,0M mostraram que elas s?o homopol?meros ramificados constitu?dos de - D-Galactopiranoses unidas por liga??es b-1,6 (predominante) e b-1,3. Alguns res?duos de galactose apresentam sulfata??o em C4 ou em C6, e algumas galactoses em posi??o n?o redutora apresentam piruvata??o na forma de 3,4- O-(1?-carboxi)etilideno, cetal c?clico com cinco membro
2

Otimiza??o da extra??o de polissacar?deos sulfatados da alga vermelha Gracilaria birdiae e an?lise da atividade anticoagulante e antioxidante

Fidelis, Gabriel Pereira 12 December 2014 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-14T20:02:00Z No. of bitstreams: 1 GabrielPereiraFidelis_DISSERT.pdf: 2672661 bytes, checksum: d836949986a9f770a6728a0061945803 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-01-18T21:39:54Z (GMT) No. of bitstreams: 1 GabrielPereiraFidelis_DISSERT.pdf: 2672661 bytes, checksum: d836949986a9f770a6728a0061945803 (MD5) / Made available in DSpace on 2016-01-18T21:39:54Z (GMT). No. of bitstreams: 1 GabrielPereiraFidelis_DISSERT.pdf: 2672661 bytes, checksum: d836949986a9f770a6728a0061945803 (MD5) Previous issue date: 2014-12-12 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Polissacar?deos sulfatados (PS) da alga vermelha comest?vel Gracilaria birdiae foram obtidos atrav?s de cinco diferentes condi??es de extra??o (GB1: ?gua; GB1p: ?gua/prote?lise; GB1s: ?gua/sonica??o; GB1sp: ?gua/sonica??o/prote?lise; GB2s: NaOH/sonica??o; GB2sp: NaOH/sonica??o/prote?lise). O rendimento em massa seca (g) das extra??es aumentou na seguinte ordem: GB2sp>GB1sp>GB1p>GB2s>GB1s>GB1. A quantidade de PS extra?dos por cada condi??o, em contrapartida, aumentou em sequencia diferente: GB2sp>GB1p>GB1>GB1sp>GB1s>GB2s. Espectroscopia de infravermelho e eletroforese em gel de poliacrilamida em agarose demonstram que todas as condi??es extra?ram o mesmo polissacar?deo sulfatado. Al?m disso, com base nos dados referentes ? composi??o monossacar?dica de cada condi??o de extra??o pode-se pressupor que o uso de sonica??o fez com que se obtivesse outros polissacar?deos al?m dos PS. No teste de tempo de protrombina (PT), o qual avalia a via extr?nseca da cascata de coagula??o, nenhuma das amostras apresentou atividade anticoagulante at? uma concentra??o m?xima de 0,1 mg/mL. Por outro lado, no teste de tempo de tromboplastina parcial ativada (aPTT), cuja via da cascata de coagula??o avaliada ? a intr?nseca, todas os extratos de PS tiveram atividade positiva, com exce??o da condi??o GB2sp. A atividade anticoagulante no teste de aPTT diminuiu na seguinte sequencia: GB1sp>GB2sp>GB1p>GB1>GB1s>GB2s. O teste de capacidade antioxidante total (CAT) dos polissacar?deos sulfatados tamb?m sofreu influ?ncia das varia??es de acordo com condi??o de extra??o, visto que com Gb2s e Gb1 foram obtidos os menores valores de atividade quando comparado ?s demais condi??es de extra??o. No presente trabalho, conclui-se que as condi??es de extra??o de PS influenciam as atividades biol?gicas e na composi??o qu?mica dos PS obtidos e que portanto, o uso de uma condi??o em especial pode favorecer a obten??o de PS com uma atividade que se deseja em detrimento de outras. De acordo com os dados obtidos pode-se afirmar que NaOH/sonica??o/prote?lise foi a melhor condi??o para obter PS com atividade anticoagulante e antioxidante em Gracilaria birdiae / The sulfated polysaccharides (SP) from the edible red seaweed Gracilaria birdiae were obtained using five different condition extraction (GB1: Water; GB1p: Water/proteolysis; GB1s: Water/sonication; GB1sp: Water/sonication/proteolysis; GB2s: NaOH/sonication; GB2sp: NaOH/sonication/proteolysis. The yield (g) increased in the following order GB2sp>GB1sp>GB1p>GB2s>GB1s>GB1. However, the amount of SP extracted increased in different way GB2sp>GB1p>GB1>GB1sp>GB1s>GB2s. Infrared and electrophoresis analysis showed that all conditions extracted the same SP. In addition, monosaccharide composition showed that ultrasound promotes the extraction of other polysaccharides than SP. In the prothrombin time (PT) test, which evaluates the extrinsic coagulation pathway, none of the samples showed anticoagulant activity. While in the activated partial thromboplastin time (aPTT) test, which evaluates the intrinsic coagulation pathway, all samples showed anticoagulant activity, except GB2s. The aPTT activity decreased in the order of GB1sp>GB2sp>GB1p>GB1>GB1s>GB2s. Total capacity antioxidant (TCA) of the SP was also affected by condition extraction, since GB2s and GB1 showed lower activity in comparison to the other conditions. In conclusion, the conditions of SP extraction influence their biological activities and chemical composition. The data showed NaOH/sonication/proteolysis was the best condition to extract anticoagulant and antioxidant SPs from Gracilaria birdiae.
3

Evaluation of preanalytical variables for frozen Activated Partial Thromboplastin Time samples

Sundberg, Natalie January 2022 (has links)
Activated Partial Thromboplastin Time (APTT) is a screening method used to detect defects in the intrinsic pathway. Different preanalytical variables such as centrifugation and thawing can affect the given test results from APTT analysis. The purpose of the study was to evaluate how the results for APTT were affected when frozen citrate plasma was thawed in a heating cabinet or a water bath, and how the results for APTT were affected if the samples were single or double centrifuged before freezing. A total of 40 fresh samples were collected for each study purpose and analyzed. To study how thawing conditions affected frozen samples, aliquoted plasma was frozen at –20°C for a week and then thawed in either a water bath or in a heating cabinet. To study how single and double centrifugation affected the test results, one of the two aliquots per sample was centrifuged again while the other remained single centrifuged. The samples were then stored frozen for one week and afterwards thawed. The results showed statistically significant differences between fresh samples and frozen samples thawed in a heath incubator or water bath. Regarding centrifugation conditions, both single and double centrifugation yielded statistically significant differences in comparison to fresh plasma. All the evaluated sample treatments showed statistically significant differences in comparison to fresh samples. However, in all cases the mean percentage change was ≤10%, which indicates no clinical significance. In conclusion APTT-samples seem to be sensitive to preanalytical variables and further studies are needed to evaluate their effects.
4

Závislost derivovaného fibrinogenu na hodnotách DH u APTT a QUICK(PT) metody / Dependence of derived fibrinogen on values of DH from APTT and QUICK(PT) methods

Klus, Michal January 2013 (has links)
Hemocoagulation, blood coagulation, is an important indicator of hemostatic balance in the human body. There are many ways how to investigate blood clotting. In practice, next to the tests investigating time of coagulation cascade from view of internal way (APTT – activated partial tromboplastin time) and external way (PT – prothrombin time) is often used determining of fibrinogen concentration by Clauss method. Derived fibrinogen method determined fibrinogen concentration, too, by subtracting form the clotting curve in PT test. The reaction for Clauss method is not necessary here. Derived fibrinogen is not used much in practice. This is the reason, why the thesis related to this project will try to find relationship between concentration of fibrinogen and standard tests APTT and PT. Clinical data will be used for this.
5

Methodenvergleich zur Erfassung einer Restheparinisierung nach kardiochirurgischen Eingriffen mit Herz-Lungen-Maschine / Residual heparinization after cardiopulmonary bypass – A prospective comparison of methods

Hillmann, Nadine 14 December 2016 (has links)
No description available.

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