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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.
21

S?ntese e imobiliza??o de nanopart?culas de ouro em fibras regeneradas via exaust?o para potencial aplica??o biom?dica

Silva, Iris Oliveira da 20 February 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-26T19:01:20Z No. of bitstreams: 1 IrisOliveiraDaSilva_DISSERT.pdf: 2857420 bytes, checksum: 79699f54a821e014e634ecb96cbf1212 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-01-28T21:28:52Z (GMT) No. of bitstreams: 1 IrisOliveiraDaSilva_DISSERT.pdf: 2857420 bytes, checksum: 79699f54a821e014e634ecb96cbf1212 (MD5) / Made available in DSpace on 2016-01-28T21:28:53Z (GMT). No. of bitstreams: 1 IrisOliveiraDaSilva_DISSERT.pdf: 2857420 bytes, checksum: 79699f54a821e014e634ecb96cbf1212 (MD5) Previous issue date: 2015-02-20 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / O avan?o nanotecnol?gico na s?ntese e caracteriza??o de nanopart?culas (NP?s) tem protagonizado o desenvolvimento de novas tecnologias para diversas aplica??es de materiais em escala nanom?trica que apresentam propriedades especificas. O desenvolvimento cient?fico nas ?ltimas d?cadas na ?rea de nanotecnologia tem protagonizado a descoberta de novos materiais para as mais diversas aplica??es, em ?reas como: biom?dicas, qu?mica, ?ptica, mec?nica e t?xtil. A alta efici?ncia bactericida de nanopart?culas met?licas (Au e Ag), dentre outros metais ? bastante conhecida, devido a sua capacidade de agir no DNA de fungos, v?rus e bact?rias, interrompendo o processo de respira??o celular, tornando-os importantes meios de estudo, al?m de sua capacidade de prote??o UVA e UVB. Este trabalho tem como objetivo principal a aplica??o de um m?todo inovador na impregna??o de nanopart?culas de ouro em substrato t?xtil, funcionalizado com quitosana, pelo processo de tingimento via exaust?o, com controle de temperatura, tempo e velocidade e obten??o de caracter?sticas antimicrobianas e prote??o UV. Os substratos esgotados com solu??es coloidais de NPAu?s apresentaram colora??o lil?s e avermelhada (em malha de soja) devido a sua superf?cie de plasmon no pico em torno de 520-540 nm. As NPAu?s foram sintetizadas via s?ntese qu?mica, usando o citrato de s?dio como agente redutor e estabilizador. O material foi previamente cationizado com quitosana, um polieletr?lito natural, com a finalidade de funcionaliz?-lo para potencializar a adsor??o das NPAu, sendo usadas concentra??es de 5, 7, 10 e 20 % de ligante sobre o peso do material (SPM). Verificou-se tamb?m, atrav?s de um planejamento experimental 23 , com 3 pontos centrais, qual era o melhor processo de esgotamento dos substratos, utilizando os fatores: tempo (min.), temperatura (?C) e concentra??o do coloide (%), tendo como resposta a vari?vel for?a color?stica - K/S (KubelkaMunk) das fibras. Foram evidenciadas como melhores respostas os par?metros: concentra??o e temperatura. O substrato com NPAu foi caracterizado por DRX; An?lise t?rmica, via TGA; microestrutural via MEV/EDS evidenciando as NP na superf?cie do substrato e presen?a de ouro (Au). Observou-se tamb?m que os substratos funcionalizados com NPAu possuem boa solidez a lavagem, fator de classifica??o UPF de +50, considerado excelente e propriedade bactericida de 98,22% para staphylococcus aureus e 96,45% para klebsiella pneumoniae, comprovando que o tecido multifuncional desenvolvido, possui grande potencial de aplica??o na ?rea biom?dica / The advancement of nanotechnology in the synthesis and characterisation of nanoparticles (NP's) has played an important role in the development of new technologies for various applications of nano-scale materials that have unique properties. The scientific development in the last decades in the field of nanotechnology has sought ceaselessly, the discovery of new materials for the most diverse applications, such as biomedical areas, chemical, optical, mechanical and textiles. The high bactericidal efficiency of metallic nanoparticles (Au and Ag), among other metals is well known, due to its ability to act in the DNA of fungi, viruses and bacteria, interrupting the process of cellular respiration, making them important means of study, in addition to its ability to protect UVA and UVB. The present work has as its main objective the implementation of an innovative method in the impregnation of nanoparticles of gold in textile substrate, functionalized with chitosan, by a dyeing process by exhaustion, with the control of temperature, time and velocity, thus obtaining microbial characteristics and UV protection. The exhausted substrates with colloidal solutions of NPAu's presented the colours, lilac and red (soybean knits) due to their surface plasmon peak around 520-540 nm. The NPAu's were synthesized chemically, using sodium citrate as a reducing agent and stabilizer. The material was previously cationised with chitosan, a natural polyelectrolyte, with the purpose of functionalising it to enhance the adsorption of colloid, at concentrations of 5, 7, 10 and 20 % of the bonding agent on the weight of the material (OWM). It was also observed, through an experimental design 23 , with 3 central points, which was the best process of exhaustion of the substrates, using the following factors: Time (min.), temperature (OC) and concentration of the colloid (%), having as a response to variable K/S (ABSORB?NCIA/ Kubelka-Munk) of the fibres. Furthermore, it was evidenced as the best response, the following parameters: concentration 100%, temperature 70 ?C and time 30 minutes. The substrate with NPAu was characterised by XRD; thermal analysis using TGA; microstructural study using SEM/EDS and STEM, thus showing the NP on the surface of the substrate confirming the presence of the metal. The substrates showed higher washing fastness, antibacterial properties and UV radiation protection.
22

Mol?culas coestimulat?rias na leishmaniose visceral

Rodrigues Neto, Jo?o Firmino 27 April 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-02-29T22:53:27Z No. of bitstreams: 1 JoaoFirminoRodriguesNeto_TESE.pdf: 2194031 bytes, checksum: fb646e671a736d92f6d4e5cc3cc5acc2 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-03-02T00:38:57Z (GMT) No. of bitstreams: 1 JoaoFirminoRodriguesNeto_TESE.pdf: 2194031 bytes, checksum: fb646e671a736d92f6d4e5cc3cc5acc2 (MD5) / Made available in DSpace on 2016-03-02T00:38:57Z (GMT). No. of bitstreams: 1 JoaoFirminoRodriguesNeto_TESE.pdf: 2194031 bytes, checksum: fb646e671a736d92f6d4e5cc3cc5acc2 (MD5) Previous issue date: 2015-04-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / A leishmaniose visceral (LV) ? uma doen?a end?mica em muitos pa?ses, incluindo o Brasil. O protozo?rio Leishmania infantum ? o agente etiol?gico da LV, sendo transmitido pela picada das f?meas dos flebotom?neos, durante o repasto sangu?neo. A maioria dos indiv?duos quando expostos ao parasita n?o desenvolvem a doen?a, pois apresentam um predom?nio da resposta celular Th1. Aqueles que desenvolvem doen?a, apresentam sinais como febre, perda de peso, hepatoesplenomegalia e um comprometimento da resposta imune celular, espec?fica a ant?genos de Leishmania. N?s avaliamos se essa anergia, observada durante a doen?a ativa, poderia estar associada com altera??es nas mol?culas coestimulat?rias de linf?citos T ou em seus ligantes em mon?citos CD14+. H? aumento na porcentagem de CTLA-4 em linf?citos T CD4+ (p=0,001) e ICOS em linf?citos T CD4+ e CD8+ (p=0,002 para CD4+ e p=0,003 para CD8+) ap?s est?mulo por ant?geno sol?vel de Leishmania (SLA) na LV sintom?tica, e que h? maior porcentagem dessas mol?culas ex vivo, quando comparados indiv?duos sintom?ticos aos recuperados (p=0,04 para CTLA-4 em CD4+, e p=0,001 para ICOS em CD4+ e p=0,026 para CD8+). Al?m disso, encontramos uma maior express?o dos genes CTLA-4, OX-40 e ICOS, durante a LV ativa. As mol?culas CD40, CD80, CD86, HLA-DR e ICOSL, n?o sofrem altera??o durante a doen?a. H? produ??o de IFN-? por c?lulas de sangue perif?rico, ap?s est?mulo por SLA, em indiv?duos sintom?ticos; no entanto, h? diminui??o na raz?o entre IFN-?/IL-10, com aumento desta ap?s a cura. A observa??o do comprometimento de algumas vias de mol?culas coestimulat?rias poderia diminuir a capacidade microbicida dos fag?citos, durante a leishmaniose visceral sintom?tica, podendo facilitar a sobreviv?ncia e a prolifera??o do parasita. / Visceral leishmaniasis (VL) is endemic in many countries, including Brazil. The protozoan Leishmania infantum, is the etiological agent of VL, and is transmitted by the bite of female sandflies during the blood meal. The majority of subjects when exposed to the parasite do not develop the disease, because of development of Th1 cellular responses. Those who have develop signs of VL such as fever, weight loss, hepatosplenomegaly, have impairment of the cellular immune response, specific to the Leishmania antigens. We evaluated whether the specififc anergy during symptomatic VL, may be associated with changes in T cells costimulatory molecules or their ligands in CD14+ monocytes. There is an increase in CTLA-4 porcentage on CD4+ T lymphocytes (p=0.001) and ICOS on CD4+ and CD8+ T cells (p=0.002 to CD4+ and p=0.003 to CD8+), after stimulation by soluble Leishmania antigen (SLA) during active visceral leishmaniasis, and that there is a higher percentage of these molecules ex vivo, when comparing symptomatic to recovered individuals (p=0.04 to CTLA-4 in CD4+, and p=0.001 to ICOS in CD4+ and p=0.026 to CD8+). Moreover, we found a high gene expression of CTLA-4, OX-40 and ICOS during active VL. CD40, CD80, CD86, HLA-DR and ICOSL molecules do not suffer changes during disease. There is IFN-? production by the peripheral blood cells, after SLA stimulation, by peripheral blood cells in symptomatic subjects; however, there is a decrease of the ratio IFN-?/IL-10, which is reversed after clinical recovery. The impairment of some costimulatory molecules pathways during symptomatic VL could inhibit the ability of phagocytes to kill Leishmania and could facilitate their survival and the proliferation inside macrophages.
23

Nanopart?culas de prata conjugadas com hiclato de doxiciclina: s?ntese, caracteriza??o e avalia??o da atividade antimicrobiana contra Escherichia coli

Silva, Heloiza Fernanda Oliveira da 20 July 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-10T20:59:54Z No. of bitstreams: 1 HeloizaFernandaOliveiraDaSilva_DISSERT.pdf: 2833438 bytes, checksum: 050baf5bbc7d53ced155de155c59bd1b (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-05-12T19:57:33Z (GMT) No. of bitstreams: 1 HeloizaFernandaOliveiraDaSilva_DISSERT.pdf: 2833438 bytes, checksum: 050baf5bbc7d53ced155de155c59bd1b (MD5) / Made available in DSpace on 2016-05-12T19:57:33Z (GMT). No. of bitstreams: 1 HeloizaFernandaOliveiraDaSilva_DISSERT.pdf: 2833438 bytes, checksum: 050baf5bbc7d53ced155de155c59bd1b (MD5) Previous issue date: 2015-07-20 / Nanopart?culas de prata, NPsAg t?m sido utilizadas no combate ? resist?ncia bacteriana. A abordagem de se associar um f?rmaco ao agente estabilizador ? completamente nova. ? uma t?nica na ?rea de nanomateriais a necessidade de se remover o agente estabilizador da superf?cie da part?cula porque o mesmo consome s?tios ativos para outras adsor??es. No entanto, no presente trabalho, mostraremos que a presen?a do agente estabilizante ? extremamente ben?fica, como observado nos resultados antimicrobianos. O objetivo deste trabalho foi combinar Hiclato de Doxiciclina ?s NPsAg e avaliar o efeito antimicrobiano. A Espectroscopia na regi?o do UV-Vis mostrou deslocamento batocr?mico na banda de absor??o das NPsAg livre para as NPsAg-HDOX evidenciando a poss?vel exist?ncia de esp?cie diferente das demais. A Espectroscopia de Fluoresc?ncia forneceu a informa??o que o HDOX atuava como um supressor da emiss?o das NPsAg, a partir desses dados determinou-se a rela??o de Stern-Volmer que indicou a presen?a de HDOX na esfera de a??o, ou seja, muito pr?ximo da part?cula. A Espectroscopia de Fluoresc?ncia Resolvida no Tempo evidenciou que o HDOX n?o interagiu com a superf?cie da part?cula. A Espectroscopia de Infravermelho por Reflect?ncia Atenuada Total, FTIR-ATR mostrou um deslocamento da banda de estiramento da carbonila de amida de 1680 cm-1 para 1672 cm-1, mostrando que h? uma intera??o entre o HDOX e as NPsAg estabilizadas pelo PVP. As curvas de Espalhamento de Raios-X em baixo ?ngulo, SAXS mostraram que nas primeiras 3 horas ap?s a adi??o do HDOX ?s NPsAg n?o houve desestabiliza??o das mesmas, j? a Microscopia Eletr?nica de Transmiss?o indicou que ap?s 72 horas as part?culas sofriam um aumento na distribui??o de tamanho. Fornecendo assim, uma base a respeito do envelhecimento do combinado. A avalia??o do efeito antimicrobiano foi realizado utilizando o M?todo de Difus?o (varia??o po?o). Os in?culos utilizados foram amostras padr?o de Escherichia coli e a Staphylococcus aureus. Os resultados indicaram que todos os combinados NPsAg-HDOX apresentaram efeito antimicrobiano. Entretanto o diferencial foi o efeito contra E. coli que foi maior do que para HDOX livre. / Silver nanoparticles, AgNPs have been used to combat bacterial resistance. The approach for associate the drug to stabilizing agent is completely new. It is focus area on nanometerials necessity of removing the particle stabilizing agent because it consumes other sites active for adsorption. However, in the present study shows that the presence of the stabilizing agent is extremely beneficial as observed in antimicrobial results. The goal was to combine Doxycycline hyclate to NPsAg and evaluate the antimicrobial effect. The spectroscopy in the UV-Vis region showed bathochromic shift in the absorption band of free NPsAg for NPsAg-HDOX indicating the possible existence of different species from the others. The Fluorescence Spectroscopy provided the information that the HDOX acted as a suppressor of issuing NPsAg, from these data we determined the Stern-Volmer relationship that indicated the presence of HDOX in the sphere of action, it is very close to the particle. The Spectroscopy in Time Resolved Fluorescence HDOX showed that has no interacted with the surface of the particle. The Spectroscopy Infrared Attenuated Total Reflectance, FTIR-ATR showed a shift of the amide carbonyl stretching band of 1680 cm-1to 1672 cm-1, showing that there is an interaction between the HDOX and NPsAg stabilized by PVP. The scattering curves in small angle x-ray scattering, SAXS showed that within the first 3 hours after addition of the HDOX NPsAg. In the other hand, Transmission Electron Microscopy indicated that after 72 hours the particles suffer na increase in distribution size. Thus providing a basis regarding the aging combined. The assessment of the antimicrobial effect was performed using the diffusion method. The inoculum used was standard strains of Escherichia coli. The results indicated that all NPsAg-HDOX combined had antimicrobial effect which was greater than the free HDOX (95% confidence level).
24

Acoplamento BCS em um l?quido de Luttinger em uma dimens?o

Eneias, Ronivon Louren?o 07 July 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-31T00:01:30Z No. of bitstreams: 1 RonivonLourencoEneias_TESE.pdf: 1676046 bytes, checksum: 87e6e8368469e2f6effb374dfefd6b2b (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-02T22:51:28Z (GMT) No. of bitstreams: 1 RonivonLourencoEneias_TESE.pdf: 1676046 bytes, checksum: 87e6e8368469e2f6effb374dfefd6b2b (MD5) / Made available in DSpace on 2016-06-02T22:51:28Z (GMT). No. of bitstreams: 1 RonivonLourencoEneias_TESE.pdf: 1676046 bytes, checksum: 87e6e8368469e2f6effb374dfefd6b2b (MD5) Previous issue date: 2015-07-07 / Neste trabalho nos investigamos o efeito de um emparelhamento do tipo BCS para f?rmions livres sem spin, em 1 + 1 dimens?es. Usando t?cnicas de bosoniza??o testamos a exist?ncia de modos de quasipart?culas no estado supercondutor resultante. N?s calculamos a fun??o de Green de uma part?cula isolada, a fun??o de correla??o de pares e a condutividade ?ptica e mostramos como elas diferem das fun??es an?logas para quasipart?culas convencionais. N?s compararmos os nossos resultados com os resultados experimentais relacionados aos supercondutores de alta temperatura e mostramos que eles se encaixam qualitativamente bem com os modos de quasipart?culas observados nesses materiais. / In this work we investigate the e ect of a BCS-type pairing for free spinless fermions, in 1+1 dimension. Using bosonization techniques we test the existence of quasiparticle modes in the resulting BCS like superconducting state. We calculate the single particle Green's function, the pair correlation function, the spectral function and the optical conductivity and we show how they di er from their conventional quasiparticle analogues. We compare our results with the related experimental ndings for high temperature superconductors and we show that they t qualitatively well the observed quasiparticles modes in those materials.
25

S?ntese e caracteriza??o de nanopart?culas magn?ticas de Co e Ni com aplica??o em magneto hipertermia

Sousa, Nagilson Mendes de 14 September 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-06T20:22:53Z No. of bitstreams: 1 NagilsonMendesDeSousa_DISSERT.pdf: 26377714 bytes, checksum: 39811438b6914861990ecb38bbfc438f (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-08T19:15:26Z (GMT) No. of bitstreams: 1 NagilsonMendesDeSousa_DISSERT.pdf: 26377714 bytes, checksum: 39811438b6914861990ecb38bbfc438f (MD5) / Made available in DSpace on 2016-06-08T19:15:26Z (GMT). No. of bitstreams: 1 NagilsonMendesDeSousa_DISSERT.pdf: 26377714 bytes, checksum: 39811438b6914861990ecb38bbfc438f (MD5) Previous issue date: 2015-09-14 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Nanopart?culas (Nps) s?o importantes no estudo de novos fen?menos na f?sica e no desenvolvimento de novas aplica??es tecnol?gicas. Nanopart?culas magn?ticas met?licas tais como N?quel e Cobalto surgem como objetos promissores devido as suas aplicabilidades em v?rias ?reas da ci?ncia e tecnologia. No presente trabalho apresentamos um estudo sobre o m?todo de s?ntese, caracteriza??o estrutural e magn?tica em nanopart?culas de Ni e Co. As amostras foram preparadas pelo m?todo sol-gel modi cado e formadas nos poros do pol?mero quitosana, a redu??o ocorreu em aus?ncia de uxo de Hidrog?nio. A fase cristalina do Ni e Co ? c?bica de face centrada e seus di?- metros variaram de 59-77nm e 19-50nm, respectivamente. As superf?cies das nanopart?culas foram naturalmente passivadas com seus mon?xidos apresentando estabilidade qu?mica por longos intervalos de tempo. A estrutura formada ? do tipo n?cleo/casca, o que favoreceu as intera??es de exchange bias entre o n?cleo ferromagn?tico (FM) e a casca antiferromagn?tica (AFM). As condi??es de s?ntese foram otimizadas para obter principalmente a fase FM. Ambas NPs foram submetidas ? a??o de um campo magn?tico AC e houve aquecimento r?pido at? atingir temperatura de aproximadamente 140?C em intervalos de tempo de at? 5 min. As amostras dispersadas em ?gua, atingiram temperaturas de 40- 59?C de aquecimento em at? 10 minutos, mostrando potencial para aplica??es em hipertermia magn?tica. / Nanoparticles are importante for the study of new phenomena and for the development of new applications. Metallic magnetic nanoparticles like Cobalt and Nickel are important for their applications in nanoscience and nanotechnology. In this work, we report on the synthesis and characterization of Ni and Co nanoparticles. The nanoparticles were prepared by the modi- ed sol-gel method and were formed in the pore-network of the biopolymer quitosan. The reduction occurred in absence of H2 ux. The metallic particles and their monoxides have a face-centered- cubic structure. The metallic particles sizes ranged from 59 to 77 nm and from 19 to 50 nm for Ni and Co, respectively. Their monoxides chemically passivated the metallic cores, and after several weeks we have not observed further increase in oxidation. The synthesis method was tuned to obtain mainly the ferromagnetic phase. The system behaves like a core/shell structure with a ferromagnetic core and an antiferromagnetic shell. Exchange bias e ect was observed at temperatures below the N?el temperature. Both systems were submitted to an alternated magnetic eld and the heat released by the particles increased the temperature to 140?C in an interval of 5 min. Similar studies in samples dispersed in water increased the temperatures to 40-59?C, these results suggest that these materials are candidates for magnetic hyperthermia.
26

Nanopart?culas cati?nicas de poli (?cido l?tico) para libera??o modificada de pept?dios da pe?onha do escorpi?o Tityus serrulatus

Mesquita, Philippe de Castro 24 July 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-07-08T21:45:26Z No. of bitstreams: 1 PhilippeDeCastroMesquita_DISSERT.pdf: 4902837 bytes, checksum: f6da7808fb637146d14c266f835d467b (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-07-13T21:11:08Z (GMT) No. of bitstreams: 1 PhilippeDeCastroMesquita_DISSERT.pdf: 4902837 bytes, checksum: f6da7808fb637146d14c266f835d467b (MD5) / Made available in DSpace on 2016-07-13T21:11:08Z (GMT). No. of bitstreams: 1 PhilippeDeCastroMesquita_DISSERT.pdf: 4902837 bytes, checksum: f6da7808fb637146d14c266f835d467b (MD5) Previous issue date: 2015-07-24 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Acidentes notificados envolvendo o envenenamento por escorpi?es ainda s?o frequentes no Brasil, ocasionados principalmente pela esp?cie Tityus serrulatus, conhecido como escorpi?o amarelo. Embora os soros antiescorpi?nicos sejam produzidos rotineiramente por diversos laborat?rios oficiais, a efic?cia de sua utiliza??o depende da rapidez com que se inicia o tratamento e da efici?ncia na produ??o de anticorpos pelos animais imunizados. No presente trabalho, o desenvolvimento de nanopart?culas polim?ricas cati?nicas de poli(?cido l?tico) teve como objetivo a busca de um sistema de libera??o modificada para os pept?deos e prote?nas presentes na pe?onha do escorpi?o T. serrulatus, capaz de potencializar a produ??o de anticorpos em soro anti-veneno. As nanopart?culas cati?nicas foram obtidas por nanoprecipita??o, ap?s o estudo do efeito dos par?metros da t?cnica sobre as propriedades f?sico-qu?micas das part?culas, com a otimiza??o de um m?todo de baixa energia. A funcionaliza??o da superf?cie das nanopart?culas com a polietilenoimina hiper-ramificada foi comprovada pela an?lise de potencial zeta e possibilitou a adsor??o por intera??o eletrost?ticade diferentes tipos de prote?nas. A efici?ncia de incorpora??o de 40-80 % de albumina de sorobovino (BSA) e 100 % de pept?deos da pe?onha do escorpi?o avaliadas por espectrofotometria e eletroforese em gel de poliacrilamida, confirmou o sucesso na escolha dos par?metros do m?todo de obten??o das nanopart?culas, produzidas com tamanho entre 100 a 250 nm. A an?lise de microscopia de for?a at?mica e estudos in vitro de libera??o, mostraram que as nanopart?culas esf?ricas fornecem um perfil sustentado de libera??o das prote?nas pelo mecanismo de difus?o, que potencializou a produ??o de anticorpos antiveneno em animais imunizados com as nanopart?culas contendo a pe?onha do escorpi?o, comprovando o potencial para aplica??o in vivo das nanopart?culas. / Reported accidents involving the poisoning scorpions are still frequent in Brazil, mainly caused by Tityus serrulatus, known as yellow scorpion. Although antivenom sera are produced routinely by various government laboratories, the effectiveness of its use depends on how quickly treatment is initiated and efficiency in the production of antibodies by the immunized animals. In this study, the development of cationic polymeric nanoparticles of poly(lactic acid) aimed to create a modified delivery system for peptides and proteins of T. serrulatus venom, able to enhance the production of serum antibodies against the scorpion toxins. The cationic nanoparticles were obtained by a low energy nanoprecipitation, after study of the parameters? variations effects over the physicochemical properties of the particles. The surface functionalization of the nanoparticles with the hyperbranched polyethyleneimine was proved by zeta potential analysis and enabled the adsorption by electrostatic interaction of different types of proteins. The protein loading efficiency of 40-80 % to bovine serum albumin (BSA) and 100 % to scorpion venom peptides evaluated by spectrophotometry and polyacrylamide gel electrophoresis confirmed the success of the selected parameters established for obtainment of nanoparticles, produced with size between 100 to 250 nm. The atomic force microscopy analysis and in vitro release showed that the spherical nanoparticles provided a sustained release profile of proteins by diffusion mechanism, demonstrating the potential for application of the nanoparticles in vivo.
27

Estudo das atividades fotocatal?tica e antimicrobiana de part?culas de AgCl impregnadas com CuO obtidas via s?ntese sonoqu?mica

Andrade Neto, Nivaldo Freire de 16 June 2017 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-03-02T23:17:21Z No. of bitstreams: 1 NivaldoFreireDeAndradeNeto_DISSERT.pdf: 3043754 bytes, checksum: 81f701dde4d2487b0d56ee58677070b6 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-03-13T18:18:43Z (GMT) No. of bitstreams: 1 NivaldoFreireDeAndradeNeto_DISSERT.pdf: 3043754 bytes, checksum: 81f701dde4d2487b0d56ee58677070b6 (MD5) / Made available in DSpace on 2018-03-13T18:18:44Z (GMT). No. of bitstreams: 1 NivaldoFreireDeAndradeNeto_DISSERT.pdf: 3043754 bytes, checksum: 81f701dde4d2487b0d56ee58677070b6 (MD5) Previous issue date: 2017-06-16 / O crescimento das atividades industriais vem proporcionando um aumento na gera??o de efluentes, que fez com que ?rg?os governamentais relacionados ao meio ambiente propusessem a cria??o de marcos regulat?rios para limitar a gera??o de efluentes. Os efluentes gerados pelas ind?strias t?xteis s?o de dif?cil degrada??o por m?todos tradicionais de tratamento. Os processos oxidativos avan?ados (POAs) s?o uma alternativa eficiente para a degrada??o de poluentes org?nicos, como corantes (azul de metileno). Neste trabalho, part?culas de cloreto de prata (AgCl) impregnadas com ?xido de cobre (CuO) foram sintetizadas via m?todo sonoqu?mico. Foram preparadas composi??es molares de 1:1 e 2:1 de AgCl/CuO, respectivamente. Tais composi??es passaram por tr?s rotas de obten??o distintas. Para a caracteriza??o das part?culas, utilizou-se as t?cnicas de difra??o de raios-X (DRX), microscopia eletr?nica de varredura com emiss?o de campo (MEV-FEG), e espectroscopia UV-vis?vel (UV-vis). Para verificar a aplicabilidade do composto foram realizados nas amostras de AgCl/CuO testes fotocatal?ticos para degrada??o do corante azul de metileno e a atividade antimicrobiana frente ?s bact?rias Escherichia coli e Staphylococcus aureus. Os resultados da difra??o de raios-X confirmaram a forma??o de AgCl e CuO em todas as amostras, n?o havendo ind?cios de dopagem para nenhuma rota utilizada. Os resultados da atividade fotocatal?tica indicam que o aumento da propor??o molar de AgCl (1:1 para 2:1) acelera a degrada??o do azul de metileno em m?dia em 25%. / The growth of industrial activities has led to an increase in the generation of effluents, which led environmental agencies to propose the creation of regulatory frameworks to limit the generation of effluents. The effluents generated by the textile industries are difficult to be degraded by traditional methods of treatment. Advanced oxidative processes (POAs) are an efficient alternative for the degradation of organic pollutants such as dyes (methylene blue). In this work, silver chloride particles (AgCl) impregnated with copper oxide (CuO) were synthesized via method sonochemistry. AgCl/CuO 1:1 and 2:1 molar compositions, respectively, were prepared. Such compositions went through three distinct procurement routes. To characterize the particles, X-ray diffraction (XRD), scanning electron microscopy with field emission (SEM-FEG), and UV-visible (UV-vis) spectroscopy were performed. To verify the applicability of the compound were carried out in the samples of AgCl/CuO photocatalytic tests for degradation of the methylene blue dye and the antimicrobial activity against the bacteria Escherichia coli and Staphylococcus aureus. The results of X-ray diffraction confirmed the formation of AgCl and CuO in all samples, with no evidence of doping for any route used. The results of the photocatalytic activity indicate that increasing the molar ratio of AgCl (1:1 to 2:1) accelerates the degradation of methylene blue on average by 25%.
28

Desenvolvimento e caracteriza??o de biolubrificante a partir do ?leo de carna?ba aditivado com micropart?culas e nanopart?culas de grafite

Cavalcanti, Synara Lucien de Lima 29 January 2018 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-03-20T17:21:12Z No. of bitstreams: 1 SynaraLucienDeLimaCavalcanti_TESE.pdf: 4087598 bytes, checksum: 3742f5acd410c92f39cb86294da47261 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-03-22T13:32:34Z (GMT) No. of bitstreams: 1 SynaraLucienDeLimaCavalcanti_TESE.pdf: 4087598 bytes, checksum: 3742f5acd410c92f39cb86294da47261 (MD5) / Made available in DSpace on 2018-03-22T13:32:34Z (GMT). No. of bitstreams: 1 SynaraLucienDeLimaCavalcanti_TESE.pdf: 4087598 bytes, checksum: 3742f5acd410c92f39cb86294da47261 (MD5) Previous issue date: 2018-01-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / O lubrificante ? respons?vel por reduzir o desgaste relativo ao atrito, proteger o metal contra a oxida??o, corros?o e dissipar o calor excessivo, tornando-se essencial para o equil?brio de um sistema mec?nico, consequentemente prolongando a vida ?til de tal sistema. A origem dos ?leos lubrificantes ?, em geral, mineral sendo extra?dos a partir do petr?leo. Mas a busca por uma nova fonte de produ??o de lubrificantes faz-se necess?rio para suprir futuras demandas e diminuir os poss?veis danos ambientais. O ?leo vegetal ? um recurso renov?vel e biodegrad?vel, e a sua utiliza??o implica em vantagens nos aspectos ambientais, sociais e econ?micos, apresentando-se como uma mat?ria prima de grande potencial para a produ??o de lubrificantes. De acordo com a literatura, o ?leo vegetal de carna?ba apresenta excelentes propriedades e desempenho superior em rela??o a sua capacidade de reduzir o desgaste relativo ao atrito e a sua capacidade de dissipa??o de calor quando comparado com um ?leo comercial similar. Este projeto tem como objetivo desenvolver e caracterizar um material biolubrificante aditivado com micropart?culas e nanopart?culas de grafite a partir do ?leo de carna?ba. O ?leo de carna?ba in natura foi submetido a uma an?lise de estabilidade oxidativa, estabilidade t?rmica, e an?lise de sua composi??o qu?mica. As micropart?culas e nanopart?culas de grafite foram desenvolvidas em um moinho planet?rio de alta energia e caracterizadas atrav?s das an?lises em MEV, MEV-FEG, DRX, FRX e EDX. As concentra??es de grafite nas amostras de biolubrificante foram 0g/L, 0,5g/L e 2g/L. Para caracterizar o biolubrificante foram realizadas as an?lises da microestrutura, de massa espec?fica, viscosidade, ?ndice de acidez, estabilidade t?rmica, condutividade t?rmica e resistividade t?rmica. A efici?ncia de lubrifica??o e a capacidade de dissipa??o de calor por gradiente de temperatura foram analisadas em um sistema mec?nico simulado em bancada (EPEDRA). Diante das an?lises conclui-se que o ?leo de carna?ba in natura, BiolubC 2.0M e BiolubC 2.0N podem ser utilizados eficientemente como biolubrificantes, observadas as caracter?sticas e necessidades do sistema mec?nico. / The lubricant is responsible for reducing friction-related wear, protecting the metal against oxidation, corrosion and dissipating excessive heat, making it essential for the balance of a mechanical system, thereby prolonging the life of such a system. The origin of the lubricating oils is, in general, mineral being extracted from petroleum. But the search for a new source of lubricant production is necessary to meet future demands and reduce possible environmental damages. Vegetable oil is a renewable and biodegradable resource and its use implies advantages in environmental, social and economic aspects, presenting as a raw material of great potential for the production of lubricants. According to the literature, the carnauba oil has excellent properties and superior performance in relation to its ability to reduce friction-related wear and its heat dissipation capacity when compared to a similar commercial oil. This project aims to develop and characterize a biolubricant material added with microparticles and graphite nanoparticles from carnauba oil. The in natura carnauba oil was subjected to oxidative stability, thermal stability, and analysis of its chemical composition. The microparticles and nanoparticles were developed in a high energy planetary mill and characterized by SEM, DRX, FRX and EDX analysis. The graphite concentrations in the biolubricant samples are 0g/L, 0,5g/L and 2g/L. In order to characterize the biolubricant, microstructure, specific gravity, viscosity, acidity index, thermal stability, thermal conductivity and thermal resistivity analyzes were performed. The lubrication efficiency and the heat dissipation capacity by temperature gradient were analyzed in a simulated mechanical bench system. In view of the analysis, it is concluded that the in natura carnauba oil, BiolubC 2.0M and BiolubC 2.0N can be efficiently used as biolubricants, observing the characteristics and needs of the mechanical system.
29

Impact of the aggregation state of amphotericin B on its biopharmaceutical properties. Design of micro- and nanocarriers for oral delivery

Marcelino, Henrique Rodrigues 08 April 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-12-29T16:13:13Z No. of bitstreams: 1 HenriqueRodriguesMarcelino_TESE.pdf: 41935029 bytes, checksum: f0753c6daecb5d46efe91996e88f61a5 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-01-02T16:17:22Z (GMT) No. of bitstreams: 1 HenriqueRodriguesMarcelino_TESE.pdf: 41935029 bytes, checksum: f0753c6daecb5d46efe91996e88f61a5 (MD5) / Made available in DSpace on 2017-01-02T16:17:23Z (GMT). No. of bitstreams: 1 HenriqueRodriguesMarcelino_TESE.pdf: 41935029 bytes, checksum: f0753c6daecb5d46efe91996e88f61a5 (MD5) Previous issue date: 2016-04-08 / Esta tese foi realizada com o objetivo geral de desenvolver e a caracterizar nanocarreadores com potencial para sobrepujar as propriedades biofarmac?uticas n?o-favor?veis da anfotericina B (AmB), uma mol?cula extremamente eficaz no tratamento de infec??es sistemicas fungicas e leishmaniose, mas dif?cil de formular independentemente da via de administra??o desejada. Acredita-se que essa mol?cula hidrof?bica possui limita??es devido a pronunciada tend?ncia de agregar sob condi??es fisiol?gicas humanas. A primeira parte desta tese foi conduzida pela hip?tese de que o estado de agrega??o da AmB teria um forte impacto sobre as propriedades farmacocin?ticas da mesma. Por tal raz?o, complexos de albumina e amB foram produzidos de forma a controlar o estado de agrega??o da AmB. A estrutura dos coloides obtidos foi caracterizada atrav?s de ensaios de espectroscopia UV-Vis e dicroismo circular. Adicionalmente, o impacto do estado de agrega??o na permeabilidade intestinal e no poss?vel reconhecimento dos agregados pelo sistema imunol?gico foram investigados. A segunda parte deste trabalho teve como objetivo o desenvolvimento de micro- e nanocarreadores para sobrepor as barreiras para absor??o da AmB ap?s a sua administra??o pela via oral. Para este fim, AmB foi incorporada em micro- e nanoemuls?es para observa??o da habilidade destes sistemas de incrementar a permeabilidade intestinal de mol?culas. Tal habilidade foi avaliada atrav?s do m?todo ex vivo de C?maras de Ussing, onde o tecido intestinal ? utilizado como barreira entre duas semi-c?maras. Nenhuma permea??o foi detectada nas condi??es experimentais utilizadas. No entanto, os dados obtidos atrav?s da medidas eletrofisiol?gicas demonstraram que a velocidade da perda da viabilidade do tecido ? dependente do estado de agrega??o da AmB em contato com o tecido. Tamb?m foi observado, atrav?s dos ensaios de permeabilidade que as rotas de absor??o paracelular e transcelular devem ser rotas marginais quando a absor??o da AmB ? observada in vivo, como descrito na literatura. Como alternativas, as rotas de absor??o pela captura de agregados e part?culas pelas placas de Peyer e a rota de absor??o linf?tica t?m sido discutidas. Finalmente, um otro sistema particulado que objetiva a libera??o em n?vel de col?n e baseada na utiliza??o da xilana, um biopol?mero natural e enzimaticamente degradado. A xilana ? polissacar?deo presente em gr?os, cereais e plantas angiospermas que ? especificamente degradado na regi?o col?nica, especificamente pela microbiota l? presente. A t?cnica aplicada de forma original consiste na forma??o de uma emuls?o ?gua-?gua de xilana em presen?a de PEG, seguida por uma etapa de reticula??o com o tris?dio trimetafosfato. Atrav?s da aplica??o desta t?cnica foi poss?vel produzir part?culas ? base de xilana que podem ter seu tamanho m?dio, de forma controlada, variado entre 380 nm e 4.5 ?m, de acordo com os par?metros utilizados. Esta t?cnica tamb?m ? livre do uso de solventes org?nicos e possui potencial aplica??o para a libera??o controlada de AmB em n?vel de col?n. / This thesis is part of the development and evaluation of nanomedicines potentially able to overcome unfavorable biopharmaceutical properties of amphotericin B (AmB), a highly effective molecule used for the treatment of systemic fungal infections and leishmaniasis, but difficult to formulate efficiently, whatever the route of delivery. It is believed that this hydrophobic molecule suffers from severe limitations due to its pronounced tendency to aggregate under physiological conditions. The first part of the thesis was driven on the hypothesis that the degree of aggregation of AmB could have a strong impact on some of its pharmacokinetics properties. For this purpose albumin has been used to produce controlled complexes between albumin and AmB in order to control AmB aggregation states. The morphological characteristics of the resulting colloidal objects have been carefully characterized by UV-Vis spectroscopy and circular dichroism. Furthermore, the impact of aggregation state on both the intestinal permeability and a possibly expected recognition of the aggregates by the immunological system were investigated. The second part of this work was focused on the development of micro- and nanocarriers intended to overcome the absorption barrier raised against AmB after oral delivery. For this purpose, AmB was loaded into micro- and nanoemulsions to evaluate a possible permeability enhancement effect through the intestinal membrane, which was evaluated in ratas using the Ussing chamber model. No detectable permeation was seen in any of the experimental conditions. However, the electrophysiological data showed tissue viability losses due to the strong toxicity of AmB, that were dependent on the aggregation state of AmB when in contact with the tissue. It was also concluded from detailed permeation experiments in healthy tissues that paracellular and transcellular routes were likely to be only marginal pathways when oral absorption are observed in vivo, as reported in the literature. The likeness of other possible absorption pathways, including Peyer's patches capture and lymphatic pathway implication for aggregated particles has been discussed. Finally, another particulate system intended for colonic delivery and based on xylan, a natural and enzymatically degradable biopolymer, has been investigated. Xylan is a polysaccharide present in grains, cereals and angiosperm plants that is specifically degraded on colon region, by the microbiota. An original process consisting in a water-in-water emulsion of xylan in presence of PEG followed by a crosslinking phase using trisodium trimetaphosphate has been developed, making possible the production of xylan-based biocompatible micro- and nanospheres ranging from 380 nm to 4.5 ?m, depending on the parameters in the process. This eco-friendly process is free of harmful solvents and has potential application for the delivery of AmB at the colonic level.
30

Estudo do conceito de serendipidade como base para novas abordagens ao problema da converg?ncia prematura

Paiva, F?bio Augusto Proc?pio de 01 July 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-01-27T12:26:53Z No. of bitstreams: 1 FabioAugustoProcopioDePaiva_TESE.pdf: 11863653 bytes, checksum: ea2b87d3ec0832aff7e2d5c1c7eda033 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-01-30T12:32:55Z (GMT) No. of bitstreams: 1 FabioAugustoProcopioDePaiva_TESE.pdf: 11863653 bytes, checksum: ea2b87d3ec0832aff7e2d5c1c7eda033 (MD5) / Made available in DSpace on 2017-01-30T12:32:55Z (GMT). No. of bitstreams: 1 FabioAugustoProcopioDePaiva_TESE.pdf: 11863653 bytes, checksum: ea2b87d3ec0832aff7e2d5c1c7eda033 (MD5) Previous issue date: 2016-07-01 / Em muitos problemas de engenharia, ? comum o estudo de um tipo de processo que se comporta, via de regra, como um sistema din?mico. Esse tipo de sistema possui a peculiaridade de poder ser modelado por meio de um conjunto de equa??es que evolui ao longo do tempo para representar o comportamento modelado do sistema. Para resolver esses problemas de engenharia, diversos m?todos de Computa??o Bio-inspirada v?m sendo propostos como solu??o em diferentes contextos. Entre esses m?todos, est? uma categoria de algoritmos conhecida como Intelig?ncia de Enxames. Apesar do relativo sucesso, a maioria dos m?todos bio-inspirados enfrenta um problema muito comum conhecido como converg?ncia prematura. A converg?ncia prematura ocorre quando um enxame (ou uma popula??o) perde a sua capacidade de gerar diversidade e, como consequ?ncia, converge para uma solu??o sub-?tima, prematuramente. Na literatura, existem diversas abordagens que se prop?em a resolver esse problema. Esta tese prop?e uma nova abordagem que ? baseada em um conceito chamado serendipidade que, normalmente, ? aplicado no dom?nio dos Sistemas de Recomenda??o. Para avaliar a viabilidade da adapta??o desse conceito ao novo contexto, uma variante chamada Serendipity-Based Particle Swarm Optimization (SBPSO) foi implementada e, posteriormente, comparada com a Particle Swarm Optimization (PSO) padr?o e algumas variantes apresentadas na literatura. Para realizar os diversos experimentos computacionais, foram utilizadas 16 fun??es de benchmark bastante comuns. Em todos os experimentos, os resultados da SBPSO se mostraram promissores e apresentaram um bom comportamento de converg?ncia, superando a PSO padr?o e as variantes estudadas no que diz respeito ? qualidade da solu??o, ? capacidade de encontrar o ?timo global, ? estabilidade das solu??es e ? capacidade de reiniciar o movimento do enxame ap?s a estagna??o ter sido detectada. / IN the literature, it is common to find many engineering problems which are used to present the effectiveness of the optimization algorithms. Several methods of Bio-Inspired Computing have been proposed as a solution in different contexts of engineering problems. Among these methods, there is a class of algorithms known as Swarm Intelligence. Despite the relative success, most of these algorithms faces a common problem known as premature convergence. It occurs when a swarm loses its ability to generate diversity and consequently converges to a suboptimal solution prematurely. There are several approaches proposed to solve this problem. This doctoral thesis proposes a new approach based on a concept called serendipity. It is usually applied in the field of Recommender Systems. To validate the feasibility of adapting this concept to the new context, a variant called Serendipity-Based Particle Swarm Optimization (SBPSO) has been implemented considering two dimensions of serendipity: chance and sagacity. To evaluate the presented proposal, two sets of computer experiments were performed. Sixteen reference functions which are common in the evaluation of optimization algorithms were used. In the first set of experiments, four functions were used to compare SBPSO to Particle Swarmoptimization (PSO) and some literature variants. In the second ones, twelve other functions were used, but for high dimensionality and a larger number of evaluations of the objective function. In all experiments, the results of the SBPSO were promising and presented a good convergence behaviour with regard to: a) quality of the solution, b) ability to find the global optimum, c) stability of solutions and d) ability to resume the swarmmovement after stagnation has been detected.

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