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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.
11

The Role of Audiology Assistants in a Clinical Setting

Duran, Joseph K. 01 May 2002 (has links)
The employment of audiology assistants to relieve masters and doctoral level audiologists of routine tasks is a timely and controversial topic in our field. Berardino (2000) examined the roles of audiology assistants within Veteran’s Administration (VA) Hospitals using an e-mail survey that was sent out to VA audiologists. The results of that survey suggested that the majority of VA audiologists were in favor of the participation of audiology assistants in the clinic to varying degrees. The purpose of this survey was to determine the current attitudes of audiologists and otolaryngologists toward the role of audiology assistants in the hearing health care profession. The attitudes and opinions of otolaryngologists were of particular interest because this population had not been included in earlier surveys despite the fact that they often employ both audiologists and audiology assistants. The survey was e-mailed to a randomly selected group of audiologists and otolaryngologists. In addition to general opinion and demographic questions, participants were asked to rate specific audiology tasks on a six-point scale ranging from very appropriate to very inappropriate. Results indicate that audiologists and otolaryngologists generally agree on which tasks are appropriate for audiology assistants; however, audiologists feel audiology assistants may be a threat to the profession of audiology whereas otolaryngologists do not.
12

Synthesis of Cafestol and Ent-kaurene Derivatives

Almazrua, Rakan Nasser 25 April 2022 (has links)
No description available.
13

Funktionelle und genetische Variabilität bei der zytotoxischen Wirkung von Nukleosid-Analoga / Functional and genetic variability in the cytotoxic action of nucleosid analogues

Kuschel, Christian 16 May 2012 (has links)
No description available.
14

Efeito do Ar Incorporado em Argamassas de Revestimentos / Effect of Air Incorporated in Mortars Jackets

RESENDE, Paulo Sérgio de Oliveira 29 October 2010 (has links)
Made available in DSpace on 2014-07-29T15:18:20Z (GMT). No. of bitstreams: 1 PAULO SERGIO DE OLIVEIRA RESENDE.pdf: 2092987 bytes, checksum: 9b30d95e68cb24f8eac4b2f3156d8b73 (MD5) Previous issue date: 2010-10-29 / The present study contemplates in a scient ific way the act ion of air ent raining agents in mortars produced in laboratory and the ef fects on the coat ings appl ied on porous subst rates (ceramic blocks, concrete blocks) . This is an experimental work, aiming to test the effect of the air entraining agents in fresh mortars, hardened state and the remaining ai r in coat ing appl ied. The variables were: ai r content , type of subst rate and sur face finishing. Adopt ing a methodology for varying levels of ent raining ai r, keeping fixed the subst rate, the form of appl icat ion and the type of sur face finishing, evaluat ing the propert ies of mortars in order to obtain the ideal air content of dosage. Other studies were done after evaluat ion of opt imal ai r content , keeping i t as a fixed condi t ion and varying the type of subst rate, appl icat ion type and the type of sur face finishing, in order to analyze thei r inter f erence in the amount of remaining ai r, as wel l as such inter ference coat ing appl ied. / O presente t rabalho aborda a ação da incorporação de ar em argamassas de revest imentos, produzidas em laboratór io, e seus efei tos em revest imentos apl icados sobre substratos porosos (bloco cerâmico, bloco de concreto, super fície de concreto). Trata -se de um estudo experimental , onde se aval ia os efei tos dos adi t ivos incorporadores de ar em argamassas nos estados f resco, no estado endurecido e como revest imento apl icado sendo que as principais variáveis estudadas foram: t ipo de adi t ivo, teor de ar, t ipo de sub st rato, t ipo de cimento e o t ipo de acabamento super ficial . Aval iou-se a inf luência da variação do teor de ar nas propriedades mecânicas das argamassas e revest imentos e ver ificou-se a variação do t ipo de acabamento super ficial influencia na resistência de aderência à tração e no desgaste do corte . Na aval iação das caracter íst icas físicas e das propriedades mecânicas dessas argamassas obteve-se um valor para o teor ót imo de ar incorporado. O estudo que teve como condições fixas o t ipo de subst rato padrão e a forma de apl icação, variando o teor de ar incorporado. Como resul tado constatou -se que há um teor ót imo para incorporação de ar , acima do qual as propriedades no estado f resco e endurecido começam a ser prejudicadas, devendo -se evi tar tais teores. Foi possível ainda veri f icar um melhor desempenho das argamassas com ar incorporado com relação à permeabi l idade à água quando comparadas com as argamassas sem adi t ivo incorporador de ar .
15

Synthèse asymétrique de l’épi-jasmonate de méthyle et de son énantiomère (ent-épi-jasmonate de méthyle) par voie chimique et enzymatique / Asymmetric synthesis of methyl epi-jasmonate and its enantiomer (methyl ent-epi-jasmonate) by chemo-stereoselective and enzymatic routes

Deau, Emmanuel 08 April 2011 (has links)
Les jasmonates de méthyle sont des oxylipines asymétriques impliquées dans les mécanismes de défense, de développement et de régulation des organismes photosynthétiques terrestres ou marins face à des stress biotiques et abiotiques. Parmi les quatre stéréoisomères, seuls l’épi-jasmonate et l’ent-épi-jasmonate de méthyle possèdent de bonnes propriétés organoleptiques mais aussi une forte activité phytohormonale permettant l’élicitation de métabolites secondaires bioactifs. En ciblant spécifiquement une hexokinase mitochondriale régulant le métabolisme des cellules cancéreuses, les jasmonates de méthyle constituent d’excellents candidats pour de nouveaux agents thérapeutiques. Dans la recherche constante de nouvelles molécules thérapeutiques issues du milieu naturel, notre laboratoire s’est donc focalisé sur la synthèse énantiosélective de l’épi-jasmonate et l’ent-épi-jasmonate de méthyle, au départ de diols bicycliques homochiraux monoprotégés dérivant du cyclooct-1,5-diène.Afin d’obtenir ces diols bicycliques énantiopurs, une stratégie innovante a consisté en l’étude de la réaction d’électrocyclisation du méso-époxyde dérivé du cyclooct-1,5-diène assistée par des ligands chiraux métallés diversement fonctionnalisés, les catalyseurs de Jacobsen. En mettant à profit notre savoir-faire sur les désymétrisations enzymatiques, une stratégie parallèle optant pour la résolution énantiosélective de diols homochiraux monocycliques, ou de diols bicycliques C2-symétriques nous a permis d’accéder à des silanyloxyindèn-5-ones chirales, précurseurs clé des cis-jasmonates de méthyle énantiopurs. Enfin, la synthèse racémique de deux jasmonoïdes clé, la (±)--jasmolactone, puis le (±)-épi-jasmonate de méthyle a été validée en 15 étapes à partir du cyclooct-1,5-diène. / Methyl jasmonates are asymmetric oxylipins involved in defensive, developmental and regulative mechanisms of terrestrial and marine photosynthetic organisms in response to biotic and abiotic challenges. Among the four stereoisomers, only methyl epi-jasmonate and ent-epi-jasmonate show good organoleptic properties but also phytohormonal activity allowing the elicitation of bioactive secondary metabolites. Because they specifically target a mitochondrial hexokinase regulating the metabolism of cancer cells, methyl jasmonates have become excellent candidates as new therapeutic agents. With a constant attention on new therapeutic agents derived from the natural environment, our laboratory has focused on the enantioselective synthesis of methyl epi-jasmonate and ent-epi-jasmonate using monoprotected homochiral diols derived from cyclooct-1,5-diene.In order to obtain these chiral bicyclic diols, an innovative strategy has involved the study of the chemo-stereoselective electrocyclization of the cyclooct-1,5-diene-derived meso-epoxide assisted by chiral metallated ligands known as Jacobsen’s catalysts. Taking advantage of our knowledge of enzymatic desymmetrization, a second strategy opting for the enantioselective resolution of monocyclic homochiral diols or C2-symmetric bicyclic diols led access to chiral silanyloxyinden-5-ones, key precursors to chiral methyl cis-jasmonates. Meanwhile, the racemic synthesis of (±)--jasmolactone and methyl (±)-epi-jasmonate was validated in 15 steps starting from cyclooct-1,5-diene.
16

Determina??o de tanino condensado em leguminosas forrageiras tropicais como indutor da fermenta??o ruminal e de sua a??o anti-helm?ntica / Pires. Determina??o de tanino condensado em leguminosas forrageiras tropicais como indutor da fermenta??o ruminal e de sua a??o antihelm?ntica

Pereira, Tatiana Pires 27 July 2016 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-10-18T12:35:34Z No. of bitstreams: 1 2016 - Tatiana Pires Pereira.pdf: 2546753 bytes, checksum: c1673b0ae2c6812a3f60faa79b5fae75 (MD5) / Made available in DSpace on 2017-10-18T12:35:34Z (GMT). No. of bitstreams: 1 2016 - Tatiana Pires Pereira.pdf: 2546753 bytes, checksum: c1673b0ae2c6812a3f60faa79b5fae75 (MD5) Previous issue date: 2016-07-27 / Funda??o Carlos Chagas Filho de Amparo ? Pesquisa do Estado do RJ - FAPERJ / This work was divided in four chapters, in which the first was performed with the goal of quantifying the condensed tannin (CT) content by the Stiasny?s reaction and to determine the classes of secondary metabolites present by the phytochemical prospection technique and magnetic resonance in the tropical forage legumes Cajanus cajan (guandu - GUA), Gliricidia sepium (gliricidia - GLI), Flemingia macrophylla (flemingia - FLE), Cratylia arg?ntea (cratilia - CRA), Mimosa caesalpineafolia (sabi?) (this legume divided into bark and leaf fraction ? SABc and SABf) among the treatments. The extracts obtained were divided into: total extract, number of Stiasny (NS), CT and non-tannins. The FLE, CRA, GUA,GLI, SABf and SABc had obtained the following values for total extract: 13.20; 13.06; 8.28; 14.73; 15.67 and 6.22%, respectively. The reactivity by NS, in the same order of legumes, was 11.25; 4.54; 7.37; 6.70; 23.06 and 71.62%, whereas the CT presented the following values: 1.52; 0.59; 0.61; 0.96; 3.6 and 4.43%, and non-tannin was 11.68; 12.46; 7.67; 13.75; 12.07 and 1.76%, respectively. The following classes of secondary metabolites were identified with greater evidence: saccharides, carbohydrates, non-protein amino acids and glicos?deos cardioativos. For the CT, the intensity was low for most of the legumes, with greater content in CRA, GUA and SABf. The wain compound in the extracts was methyl-inositol (sugar). The second chapter had the objective of assaying in the legumes mentioned above and one more specie, Stylosanthes spp. (estilosantes-EST), condensed tannin (CT) constituents, with the use of organic solvents, soluble CT (ECT), CT adhered to protein (PBCT), CT adhered to fiber (FBCT), and total CT (TCT), CT structural pro-pelargonidin (PP); prodelfinidin (PD) and procyanidin (PC), molecular weight (polymerization degree (DP), molecular distance distributed of the polymer (PDI); average weight of molecular mass (Mw), and average number of molecular mass (Mn), and the biological activity through precipitated proteins by phenols (PPP). The variables ECT, PBCT, and TCT presented were influenced by different species (P?0.05). The FBCT fraction was not found in the legumes. Molecular weights (DP, PDI, Mw e Mn) were affected by the different species (P?0.05), ranging from 737 to 1168 da. The structural characteristics (PP, PD, PC and PD:PC) varied among the species. In the third chapter I evaluated methanogenesis (total methane (CH4total)), incubated (CH4inc) and fermented (CH4ferm) and ruminal fermentation parameters total gas production (PGT), pH, ammonium (N-NH3), short-chain fatty acids (SCFA) and in vitro organic matter disappearance (IVOMD) as they related to CT present in the legumes and Urochloa brizantha cv. marandu hay as control (CTL). The effect of polyethylene glycol (PEG) on the leaf fraction of sabi? was tested as well, which had a CT content of 15.97%. No alteration in the pH (P?0.05) for the treatments evaluated. However, a decrease of total gas and methane production for all the treatments with presence of CT (P?0.05). When PEG was added, there was a 27.01 (8% PEG) and 35.01 (16% PEG) increase in total gas production and 3.59 (8% PEG) and 4.15 (16% PEG) of methane production. GUA, FLE, SABc and SABf were capable of modifying (P?0.05) the content of NH3-N (mg/dL), along with the CTL, which also presented lower values compared to legumes with no or only traces of CT (ETL, CRA and GLI). There was significant difference (P?0.05) for IVOMD between the legumes and control, it was observed lower disappearance (P?0.05) for FLE, GUA and SABf in relation to CTL, while SABc did disappear. The SABf IVOMD was affected by the addiction of PEG. There was lower digestibility for FLE, GUA and SABf in relation to the CTL, while the bark fraction of SAB did not disappear at all. On the SCFA profile, there was difference (P?0.05) among the treatments evaluated, with lower values for the legumes with presence of CT. In the fourth chapter I tested the effect of CT from the legumes in study (FLE, CRA, GUA, GLI, EST, SABf and SABc) on larval migration inhibition (LMI) in vitro, on the infective larvae L3 of the nematode Haemonchus contortus (HC), compared with Ivermectin and a negative control (rumen fluid and buffer). Among the legumes studied, SABf and GUA did not differ (P?0.05), with the greater (P?0.05) LMI percentage (34.75% and 34.33%) than the other entries. The legumes GUA, FLE and SABc did not differ (P?0.05), presenting moderate values of LMI (30.25%, 30.0% and 29.75%, respectively). Among the legumes studied, the lowest LMI percentage was CRA (18.46%), GLI (23.75%) and negative control (rumen fluid and buffer), with values near (P?0.05) from to Ivermectin (22.0%). / Este trabalho foi dividido em quatro cap?tulos. O primeiro realizou-se com o objetivo de quantificar o teor de tanino condensado (TC) atrav?s da Rea??o de Stiasny e conhecer as classes de metab?litos secund?rios presentes pela t?cnica de prospec??o fitoqu?mica e resson?ncia magn?tica nas leguminosas forrageiras tropicais Cajanus cajan (guandu-GUA), Gliricidia sepium (gliricidia-GLI), Flemingia macrophylla (flemingia-FLE), Cratylia arg?ntea (cratilia-CRA), Mimosa caesalpineafolia (sabi?) sendo que essa leguminosa tinha a fra??o casca e folha (SABc e SABf) entre os tratamentos. Os extratos obtidos foram divididos em: extrato total, n?mero de Stiasny (NS), TC e n?o taninos. A FLE, CRA, GUA, GLI, SABf e SABc apresentaram os valores para o extrato total 13,20; 13,06; 8,28; 14,73; 15,67 e 6,22%, respectivamente. A reatividade pelo NS, na mesma ordem das leguminosas, foi de 11,25; 4,54; 7,37; 6,70; 23,06 e 71,62%, j? o TC apresentou os seguintes valores 1,52; 0,59; 0,61; 0,96; 3,6 e 4,43% e o n?o tanino foi de 11,68; 12,46; 7,67; 13,75; 12,07 e 1,76%, respectivamente. Foram identificadas as seguintes classes de compostos secund?rios em maiores evid?ncias: os sacar?deos, carboidratos, amino?cidos n?o prot?icos e os glicos?deos cardioativos. J? para o TC, a intensidade foi baixa para grande parte das leguminosas, prevalecendo maior teor para CRA, GUA e SABf. Foi constatado como componente principal nos extratos o metil-inositol (a??car). O segundo cap?tulo teve como objetivo avaliar nas leguminosas citadas acima e mais uma esp?cie, o Stylosanthes spp (estilosantes-EST), analisar os constituintes do TC com uso de solvente org?nico, tanino sol?vel (TCE), tanino aderido ? prote?na (TCPB), tanino aderido ? fibra (TCFB) e taninos condensados totais (TCT), caracter?sticas estruturais tais como: propelargonidina (PP); prodelfinidina (PD) e procianidina (PC); peso molecular (grau de polimeriza??o?(DP); dist?ncia do peso molecular distribu?do do pol?mero (PDI); peso m?dio da massa molecular (Mw); n?mero m?dio da massa molecular (Mn); al?m de determinar a atividade biol?gica, atrav?s da t?cnica de prote?nas precipit?veis por fen?is (PPP). As vari?veis TCE, TCPB e TCT apresentadas foram influenciadas pelas diferentes esp?cies (P?0,05). A fra??o TCFB n?o foi constatada nas leguminosas. Os pesos moleculares (Mw) foram influenciados pelas diferentes esp?cies (P?0,05), variando de 737 a 1168 Da. As caracter?sticas estruturais (PP, PD, PC e PD:PC) tiveram varia??o entre as esp?cies estudadas. Objetivou-se com o terceiro cap?tulo avaliar a metanog?nese (metano total (CH4-total), incubado (CH4 inc.) e fermentado (CH4 ferm.) e os par?metros de fermenta??o ruminal (produ??o de g?s total (PGT), pH, am?nia (N-NH3), ?cidos graxos de cadeia curta (AGCC) e digestibilidade in vitro da mat?ria org?nica (DIVMO) frente aos TC presentes nas leguminosas e feno de Urochloa brizantha cv. marandu como controle (CTL). Foi testado tamb?m o efeito do polietileno glicol (PEG) sobre a fra??o folha do sabi?, que teve conte?do de TC de 15,97%. N?o foi observado altera??o no pH (P?0,05) para os tratamentos avaliados. No entanto, foram observadas diminui??o da produ??o total de g?s e produ??o de metano para todos os tratamentos com presen?a de TC (P?0,05). Para o tratamento com PEG houve aumento de 27,01 (8% PEG) e 35,01 (16% PEG) na produ??o total de g?s e 3,59 (8% PEG) e 4,15 (16% PEG) na produ??o de metano. GUA, FLE, SABc e SABf foram capazes de modificar (P?0,05) a concentra??o de N-NH3 (mg/dL) juntamente com o CTL, que tamb?m apresentou valores inferiores comparado as leguminosas com tra?os e aus?ncia do TC (ETL, CRA e GLI). Houve diferen?a (P?0,05) para DIVMO entre as leguminosas e o controle, observou-se menor digestibilidade (P?0,05) para FLE, GUA e SABf, em rela??o ao CTL, n?o sendo digest?vel o SABc. A DIVMO foi afetada pela adi??o de PEG na dieta do SABf. No perfil dos AGCC houve diferen?a (P?0,05) para os tratamentos avaliados, com menor valor para as leguminosas com presen?a de TC. O quarto cap?tulo teve como objetivo testar o efeito da t?cnica de inibi??o da migra??o larval (IML) in vitro do TC proveniente das leguminosas em estudo (FLE, CRA, GUA, GLI, EST, SABf e SABc) sobre as larvas infectantes L3 do nemat?de o Haemonchus contortus (HC) comparando com Ivermectina e controle negativo (l?quido ruminal e tamp?o). Entre as leguminosas estudadas o SABf e GUA n?o diferiram entre si (P?0,05), com as maiores porcentagens IML (34,75% e 34,33%). As leguminosas GUA, FLE e SABc n?o diferiram entre si (P?0,05), apresentando moderados valores de IML (30,25%, 30,0% e 29,75%, respectivamente). Entre as leguminosas estudadas a menor porcentagem de IML foi para CRA (18,46%), GLI (23,75%) e controle negativo (l?quido de r?men e tamp?o) valores pr?ximos do controle positivo com Ivermectina (22,0%).
17

LES RESEAUX NUMERIQUES EDUCATIFS, REGULATEURS, ACTEURS ET VECTEURS DE L'EVOLUTION DES PRATIQUES ET DE L'ORGANISATION DES ETABLISSEMENTS ET DE L'INSTITUTION SCOLAIRES

Puimatto, Gérard 07 June 2006 (has links) (PDF)
Cette thèse décrit comment divers réseaux, regroupés plus ou moins artificiellement sous le terme générique de réseau numérique éducatif, se sont développés dans le système scolaire français de 1987 à 2005.<br />Son premier objet est de montrer comment les contributions de la télématique, des réseaux locaux, d'Internet, des Intranet et des espaces numériques se sont ajoutées les unes aux autres pour former un ensemble stratifié. Le second est d'examiner comment ces réseaux se sont installés comme une composante du développement d'une communication scolaire médiatisée.<br />Ce processus est appréhendé sous les éclairages de la technique, des usages et de l'organisation, selon des niveaux de développement qui se déplacent progressivement de l'individu et de l'établissement vers d'autres échelles : l'académie, le territoire, la collectivité, le système éducatif. <br />La démarche de recherche s'inspire de la théorie de l'acteur-réseau appliquée dans une perspective visant à examiner les modalités d'innovations sociotechniques. La globalité de l'approche « du » réseau considéré comme un processus d'innovation conduit à cerner son cadre fonctionnel dans sa construction et son évolution. Les modalités de réalisation de l'alliage sociotechnique montrent la diversité et l'importance des enjeux et des acteurs. Les processus itératif de controverses et d'alignements stratégiques qui les animent révèlent de quelle manière le réseau numérique éducatif devient un facteur d'unité technique, éducative et stratégique.<br />Les travaux conduits mettent en évidence cinq tendances lourdes : l'organisation progressive d'une architecture globale d'information, l'affirmation de l'importance d'une démarche stratégique, des dynamiques d'usage qui passent au second, une logique d'industrialisation et une extension progressive du domaine scolaire vers le domicile. Leur caractère concomitant est déterminant dans un processus général de globalisation et de banalisation des fonctions communicationnelles scolaires.
18

The role of audiology assistants in a clinical setting [electronic resource] / by Joseph K. Duran.

Duran, Joseph Kevin January 2002 (has links)
Professional research project (Au.D.)--University of South Florida, 2002. / Title from PDF of title page. / Document formatted into pages; contains 35 pages. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: The employment of audiology assistants to relieve masters and doctoral level audiologists of routine tasks is a timely and controversial topic in our field. Berardino (2000) examined the roles of audiology assistants within Veteran's Administration (VA) Hospitals using an e-mail survey that was sent out to VA audiologists. The results of that survey suggested that the majority of VA audiologists were in favor of the participation of audiology assistants in the clinic to varying degrees. / The purpose of this survey was to determine the current attitudes of audiologists and otolaryngologists toward the role of audiology assistants in the hearing health care profession. The attitudes and opinions of otolaryngologists were of particular interest because this population had not been included in earlier surveys despite the fact that they often employ both audiologists and audiology assistants. The survey was e-mailed to a randomly selected group of audiologists and otolaryngologists. In addition to general opinion and demographic questions, participants were asked to rate specific audiology tasks on a six-point scale ranging from very appropriate to very inappropriate. / Results indicate that audiologists and otolaryngologists generally agree on which tasks are appropriate for audiology assistants; however, audiologists feel audiology assistants may be a threat to the profession of audiology whereas otolaryngologists do not. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.
19

Localisation of equilibrative nucleoside transporter 3 (ENT3) in mouse brain

Roberts, Lauren Emilienne 12 January 2015 (has links)
Adenosine is an essential purine nucleoside of particular importance within heart and brain. The widespread and diverse actions of adenosine, driven by activation of cell surface receptors, include regulation of sleep/arousal and neuroprotective properties. The mechanisms involved in regulating adenosine concentrations remain poorly understood but are critical to signaling pathways as they determine the availability of adenosine at corresponding receptors within the extracellular space. The equilibrative nucleoside transporter (ENT) family, bi-directional, Na+-independent nucleoside transporters, are key components in both the release and uptake of adenosine. This study has been conducted to investigate ENT3, a novel member of the ENT family. Our work has demonstrated ENT3 to be expressed throughout brain, located in cortex, cerebellum, striatum and hippocampus, at similar levels. Neurons and astrocytes, but not microglia, showed intracellular ENT3 localisation. This was confirmed by differential centrifugation, of cortex and cerebellum, which suggests ENT3 to be found within the cytoplasm.
20

Obten??o de sistemas multiparticulados de isoniazida revestidos com pol?mero de libera??o ent?rica

Freire, F?tima Duarte 21 September 2009 (has links)
Made available in DSpace on 2014-12-17T14:16:24Z (GMT). No. of bitstreams: 1 FatimaDF_resumo.pdf: 203448 bytes, checksum: 85b1056cddeab5f9a1555fe6c360a75b (MD5) Previous issue date: 2009-09-21 / Known for thousands of years, tuberculosis (TB) is the leading cause of mortality by a single infectious disease due to lack of patient adherence to available treatment regimens, the rising of multidrug resistant strains of TB (MDR-TB) and co-infection with HIV virus. Isoniazid and rifampicin are the most powerful bactericidal agents against M. tuberculosis. Because of that, this couple of drugs becomes unanimity in anti-TB treatment around the world. However, the rifampicin in acidic conditions in the stomach can be degraded rapidly, especially in the presence of isoniazid, which reduces the amount of available drug for absorption, as well as its bioavailability, contributing to the growing resistance to tuberculostatic drugs. Rifampicin is well absorbed in the stomach because of its high solubility between pH 1 and 2 and the gastric absorption of isoniazid is considered poor, therefore it is mostly intestinal. This work has as objective the development of gastro-resistant multiple-systems (granules and pellets) of isoniazid aiming to prevent the contact with rifampicin, with consequent degradation in acid stomach and modulate the release of isoniazid in the intestine. Granules of isoniazid were obtained by wet method using both alcoholic and aqueous solutions of PVP K-30 as aggregating and binder agent, at proportions of 5, 8 and 10%. The influence of the excipients (starch, cellulose or filler default) on the physical and technological properties of the granules was investigated. The pellets were produced by extrusionesferonization technique using isoniazid and microcrystalline cellulose MC 101 (at the proportion of 85:15) and aqueous solution of 1% Methocel as platelet. The pellets presented advantages over granular, such as: higher apparent density, smaller difference between apparent and compaction densities, smoother surface and, especially, smaller friability, and then were coated with an organic solution of Acrycoat L 100 ? in a fluidized bed. Different percentages of coating (15, 25 and 50%) were applied to the pellets which had their behavior evaluated in vitro by dissolution in acidic and basic medium. Rifampicin dissolution in the presence of uncoated and coated isoniazid pellets was evaluated too. The results indicate that the gastro resistance was only achieved with the greatest amount of coating and isoniazid is released successfully in basic step. The amount of rifampicin in the dissolution medium when the isoniazid pellets were not coated was lower than in the presence of enteric release pellets. Therefore, the polymer Acrycoat L 100 ? was efficient for coating with gastro-resistant function and can solve the problem of low bioavailability of rifampicin and help to reduce its dosage / Conhecida h? milhares de anos, a tuberculose (TB) ? a principal causa de mortalidade por uma ?nica doen?a infecciosa devido ? falta de ades?o dos pacientes aos esquemas terap?uticos dispon?veis, o aparecimento de cepas multiresistentes e a co-infec??o com o v?rus HIV. A isoniazida e a rifampicina possuem o maior poder bactericida frente ao M. tuberculosis, sendo por isso unanimidade no tratamento anti-TB em todo o mundo. No entanto, a rifampicina em condi??es ?cidas do est?mago degrada-se rapidamente, principalmente na presen?a da isoniazida, diminuindo a quantidade de f?rmaco dispon?vel para absor??o bem como a sua biodisponibilidade, contribuindo para a resist?ncia crescente aos f?rmacos tuberculost?ticos. A rifampicina ? bem absorvida no est?mago devido ? sua alta solubilidade entre pH 1 e 2 e a absor??o g?strica da isoniazida ? considerada pobre, sendo ent?o, majoritariamente intestinal. O presente trabalho teve como objetivo o desenvolvimento de sistemas multiparticulados (granulados e p?letes) de isoniazida gastrorresistentes visando evitar contato da rifampicina com isoniazida e conseq?ente degrada??o no meio ?cido estomacal bem como modular a libera??o da isoniazida no intestino. Granulados de isoniazida foram obtidos por via ?mida utilizando solu??o alco?lica e solu??o aquosa de PVP K-30 como agente agregante/aglutinante, nas propor??es 5, 8 e 10%. A influ?ncia do excipiente (amido, celulose ou aus?ncia de diluente) sobre as propriedades f?sicas e tecnol?gicas dos granulados foi investigada. Os p?letes foram produzidos pela t?cnica de extrus?o-esferoniza??o utilizando isoniazida e Celulose MC 101 (na propor??o 85:15) e solu??o aquosa de Methocel 1% como agregante. Os p?letes apresentaram vantagens em rela??o aos granulados, como: maior densidade aparente, menor diferen?a entre as densidades aparente e de compacta??o, superf?cie mais lisa e, principalmente, menor friabilidade, sendo ent?o revestidos com uma solu??o org?nica de Acrycoat L 100? em leito fluidizado. Diferentes percentuais de revestimento (15, 25 e 50%) foram aplicados aos p?letes, os quais tiveram seus comportamentos avaliados in vitro por dissolu??o em meio ?cido e b?sico. Em seguida, a dissolu??o da rifampicina em meio ?cido na presen?a da isoniazida em p?letes n?o revestidos e p?letes revestidos foi avaliada tamb?m. Os resultados indicam que a gastrorresist?ncia foi obtida somente com a maior quantidade de revestimento, sendo a isoniazida liberada com sucesso na etapa b?sica. A quantidade de rifampicina dissolvida quando associada a p?letes de isoniazida n?o revestidos foi menor do que a observada na presen?a de p?letes de libera??o ent?rica. O pol?mero Acrycoat L 100? mostrou-se eficiente para o recobrimento com a fun??o de gastrorresist?ncia, podendo resolver o problema da baixa biodisponibilidade da rifampicina assim como ajudar a diminuir a dosagem utilizada

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