Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-12-04T20:41:48Z No. of bitstreams: 1 KayoDiogenesDeAzevedoSilva_DISSERT.pdf: 2312119 bytes, checksum: 0a5f0d4a0645de7bdb4ab990bbb4f59d (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-12-07T20:45:07Z (GMT) No. of bitstreams: 1 KayoDiogenesDeAzevedoSilva_DISSERT.pdf: 2312119 bytes, checksum: 0a5f0d4a0645de7bdb4ab990bbb4f59d (MD5) / Made available in DSpace on 2017-12-07T20:45:07Z (GMT). No. of bitstreams: 1 KayoDiogenesDeAzevedoSilva_DISSERT.pdf: 2312119 bytes, checksum: 0a5f0d4a0645de7bdb4ab990bbb4f59d (MD5) Previous issue date: 2017-07-31 / A doen?a de Parkinson (DP) ? uma patologia neurodegenerativa que acomete principalmente indiv?duos do sexo masculino com o avan?ar da idade. A DP se caracteriza por diversos sintomas motores como tremores, bradicinesia, rigidez e altera??es posturais. Al?m destes, sintomas cognitivos como d?ficits de aten??o e mem?ria, dem?ncia e altera??es de humor tamb?m est?o presentes. ? poss?vel perceber marcada mudan?a na arquitetura do sono de pacientes com DP. O horm?nio melatonina sintetizado principalmente pela gl?ndula pineal localizada no Epit?lamo ? considerado um dos horm?nios que induzem a fase de sono dos organismos. Sua a??o ocorre ap?s se ligar a receptores espec?ficos, MT1 e MT2. No presente estudo foram utilizados 15 ratos machos de meia idade (10 meses) da esp?cie Wistar, divididos em dois grupos denominados de Controle (CTR) e Reserpina (RES). Esses animais foram submetidos a um protocolo cr?nico de 20 inje??es de reserpina, com o intuito de criar sintomatologias semelhantes a DP. Durante o protocolo experimental os animais foram avaliados atrav?s de teste de catalepsia. Com o fim do tratamento os animais foram sacrificados e submetidos a procedimento imunistoquimico para identifica??o dos receptores MT1 e MT2 em 5 ?reas do sistema nervoso central relacionadas diretamente com o ciclo do sono e com sintomas mais evidentes da DP, sendo elas, NE, NSQ, VLPO, SN e ZSPV. Nossos resultados mostraram que durante o per?odo de tratamento os animais do grupo reserpina apresentaram consider?vel e progressivo d?ficits motores que se acentuaram nos dias sete, oito, nove e dez de inje??es. Nossas analises imunoistoqu?micas mostraram que ocorre significativa redu??o da express?o de receptores de melatonina nos animais reserpina em todos os n?cleos avaliados, entretanto, novos estudos s?o necess?rios para uma melhor compreens?o do real motivo dessa diminui??o de express?o de receptores e se esta diminui??o tem efeito significativo nas altera??es do sono verificadas nos pacientes com DP. / Parkinson's disease (PD) is a neurodegenerative disorder that mainly affects males with advancing age. PD is characterized by several motor symptoms such as tremors, bradykinesia, stiffness and postural changes. In addition to these, cognitive symptoms such as attention and memory deficits, dementia and mood changes are also present. It is also possible to notice a marked change in the sleep architecture of patients with PD. The hormone melatonin synthesized mainly by the pineal gland located in the thalamus is considered one of the hormones that induce the sleep phase of the organisms. Its action occurs after binding to specific receptors, MT1 and MT2. In the present study, 15 male Wistar rats (10 months) were divided into two groups called Control (CTR) and Reserpine (RES). These animals were submitted to a chronic protocol of 20 injections of reserpine, in order to create symptoms similar to PD. During the experimental protocol the animals were evaluated by catalepsy test. At the end of the treatment the animals were sacrificed and submitted to an immunohistochemical procedure to identify the MT1 and MT2 receptors in 5 areas of the central nervous system related directly to the sleep cycle and with more evident symptoms of PD, VLPO, SN and ZSPV. Our results showed that during the period of treatment the animals of the reserpine group presented a considerable and progressive motor deficit that were accentuated on days seven, eight, nine and ten of injections. Our immunohistochemical analyzes have shown that there is a significant reduction in the expression of melatonin receptors in the reserpine animals in all evaluated nuclei, however, new studies are necessary to better understand the real reason for this decrease in receptor expression and whether this decrease has a significant effect on Observed in patients with PD.

In this work we present the results of the analysis of the surface structures and absorption properties with respect to the CO and O2 molecules of the Sn/Rh and Rh/SnO2 model systems. In the part dedicated to the Sn structures on Rh surfaces with two different orientations - Rh(110) and Rh(111) - we have investigated the development of the core electron levels and valence band during the development of surface reconstructions and absorption of CO molecules. The surface reconstructions of the Sn/Rh(110) systems were studied for the first time. Difference in behaviour w.r.t. Sn/Rh(111) was observed and explanation offered. Finally, on in-situ prepared epitaxial SnO2 layers, the surface reconstruction (4×1) was observed. The CO adsorp- tion properties of Rh on polycrystalline and epitaxial SnO2 layers were also studied and difference in behaviour explained.

Submitted by Edileide Reis (leyde-landy@hotmail.com) on 2013-04-23T12:46:56Z No. of bitstreams: 1 Luciene Carvalho.pdf: 878421 bytes, checksum: bd74bd7628de44a85a4f2776c0680a24 (MD5) / Made available in DSpace on 2013-04-23T12:46:56Z (GMT). No. of bitstreams: 1 Luciene Carvalho.pdf: 878421 bytes, checksum: bd74bd7628de44a85a4f2776c0680a24 (MD5) Previous issue date: 2003 / Catalisadores Pt-Re-Sn/Al2O3-Cl foram avaliados na reforma de n-octano para produção de compostos aromáticos, especialmente xilenos, e foram comparados com o catalisador monometálico (Pt/Al2O3) e catalisadores bimetálicos (Pt-Re e Pt-Sn/Al2O3) correspondentes. As amostras foram preparadas por coimpregnação e impregnações sucessivas da alumina, com as soluções dos precursores metálicos. Os sólidos foram, então, secos (120oC), calcinados (500oC, 4h, ar) e reduzidos (500oC, 4h, H2). No caso das impregnações sucessivas, os sólidos foram calcinados e reduzidos após cada adição de metal. Os catalisadores contendo rênio foram previamente sulfetados com dissulfeto de carbono. As seguintes amostras foram preparadas (0,3% p/p de cada metal): Pt/Al2O3, Re/Al2O3 e Sn/Al2O3; (Pt+Re)/Al2O3, (Pt+Sn)/Al2O3, (Re+Sn)/Al2O3 e (Pt+Re+Sn)/Al2O3, preparados por coimpregnação; Pt-Re/Al2O3, Pt-Sn/Al2O3, Pt-Re-Sn/Al2O3, Pt-Sn-Re/Al2O3, Re-Pt-Sn/Al2O3, Re-Sn-Pt/Al2O3, Sn-Pt-Re/Al2O3, Sn-Re-Pt/Al2O3, preparados por impregnações sucessivas. As funções ácida e metálica dos catalisadores foram avaliadas através das reações modelo de isomerização de n-pentano e desidrogenação de ciclohexano, respectivamente. A tiotolerância dos catalisadores foi avaliada na desidrogenação de ciclo-hexano. As amostras também foram caracterizadas por análise elementar, redução à temperatura programada (TPR), espectroscopia de infravermelho com transformadas de Fourier (FTIR) de CO adsorvido, quimissorção de H2, microscopia eletrônica de transmissão (TEM) e difração de elétrons (ED). Após os testes de isomerização de n-pentano e reforma de n-octano, as amostras foram analisadas por oxidação à temperatura programada (TPO). Observou-se que a atividade de desidrogenação da platina foi reduzida por rênio e/ou estanho, e este efeito foi mais forte com o estanho. As energias de ativação na desidrogenação de ciclo-hexano foram mais afetadas pelo estanho, que modificou os sítios ativos, produzindo outros de atividade mais baixa. Ambos os metais podem formar ligas com a platina, como mostrado pelos experimentos de TPR e ED. Estes metais tornam a platina mais rica em elétrons, diminuindo sua capacidade de quimissorção. A existência deste efeito eletrônico foi confirmada por FTIR de CO adsorvido. O enriquecimento eletrônico da platina também afetou a tiotolerância, uma vez que a ligação Pt-S tornou-se mais forte. Por isso, os catalisadores bimetálicos apresentaram uma tiotolerância mais baixa do que o catalisador monometálico, e os trimetálicos foram ainda mais susceptíveis ao envenenamento por enxofre, devido à ação conjunta dos dois metais sobre a platina. Nas amostras preparadas por coimpregnação, o envenenamento foi mais severo, por causa do melhor contato entre os metais. A função ácida também foi afetada pela presença de estanho e rênio, principalmente na forma de óxidos. Nos catalisadores trimetálicos, efeitos positivos foram encontrados quando o estanho foi adicionado primeiro, porque o óxido de estanho reduziu a quantidade de sítios ácidos mais fortes da alumina, produzindo uma acidez mais conveniente às reações de isomerização e ciclização. Dessa forma, o catalisador Sn-Pt-Re-S/Al2O3 foi o mais promissor em reforma de n-octano, com a mais alta seletividade a xilenos, maior estabilidade e produção de gases mais baixa. O catalisador trimetálico coimpregnado mostrou um desempenho similar e tem a vantagem adicional de não precisar ser previamente sulfetado. / Salvador

In this thesis, I used a two-phase gas-liquid segmented microfluidic platform to synthesize drug-loaded block copolymer nanoparticles. In Chapter 2 and 3, the anti-cancer drug 7-ethyl-10-hydroxycamptothecin (SN-38) was physically encapsulated in poly(6-methyl-caprolactone-co-ε-caprolactone)-block-poly(ethylene oxide) (P(MCL-co-CL)-b-PEO) nanoparticles with various drug-to-polymer loading ratios, under different flow conditions. The effects of chemical and flow conditions on the size, morphology, drug loading efficiency, in vitro release and cytotoxicity of the nanoparticles were determined. For various loading ratios, the intermediate total flow rate (Q = 200 µL/min) produced the smallest nanoparticle sizes and pure spheres. The various nanoparticle preparation conditions showed flow-variable release rates and cytotoxicities against MCF-7 cancer cell line. Specifically, we found that release half times of SN-38 from the nanoparticles were from τ1/2 = 0.8 to 3.3 h as the total flow rate increased from Q = 50 to 200 µL/min. We also found that most conditions of SN-38 formulations generated stronger cytotoxicity than free SN-38. As well, at short and intermediate incubation time (48 and 72 h), the cytotoxic potency of microfluidic nanoparticles prepared at Q = 200 µL/min were slightly higher than nanoparticles prepared using a conventional bulk method, while potencies of microfluidic nanoparticles prepared at higher and lower flow rates were slightly lower than the bulk control. In Chapter 4, in order to pursue even higher shear rate and increased throughput, we switched the microfabrication material to silicon/glass from polydimethylsiloxane (PDMS) used in earlier chapters, maintaining the gas-liquid microfluidic reactor design. A comparison between the two microfluidic reactor materials at constant liquid flow rate showed that channel material affected both flow behaviour and the resulting nanoparticle morphologies. A new, single-phase microfluidic strategy was also proposed in order to generate high shear, in which variable high and low shear would arise from periodic changes in channel dimensions. However, issues regarding clogging of the more narrow microchannels require future work of improvements in either reactor design or the microfabrication process. / Graduate / 2019-01-12

We present our analysis of the Type II supernova DLT16am (SN 2016ija). The object was discovered during the ongoing D < 40 Mpc (DLT40) one-day cadence supernova search at r similar to 20.1 mag in the "edge-on" nearby (D = 20.0 +/- 4.0 Mpc) galaxy NGC 1532. The subsequent prompt and high-cadenced spectroscopic and photometric follow-up revealed a highly extinguished transient, with E(B - V) = 1.95 +/- 0.15 mag, consistent with a standard extinction law with R-V = 3.1 and a bright (M-V = -18.48 +/- 0.77 mag) absolute peak magnitude. A comparison of the photometric features with those of large samples of SNe II reveals a fast rise for the derived luminosity and a relatively short plateau phase, with a slope of S-50V = 0.84 +/- 0.04 mag/50 days, consistent with the photometric properties typical of those of fast-declining SNe II. Despite the large uncertainties on the distance and the extinction in the direction of DLT16am, the measured photospheric expansion velocity and the derived absolute V-band magnitude at similar to 50 days after the explosion match the existing luminosity-velocity relation for SNe II.

Many young, massive stars are found in close binaries. Using population synthesis simulations. we predict the likelihood of a companion star being present when these massive stars end their lives as core-collapse supernovae (SNe). We focus on stripped-envelope SNe, whose progenitors have lost their outer hydrogen and possibly helium layers before explosion. We use these results to interpret new Hubble Space Telescope observations of the site of the broad-lined Type. Ic SN 2002ap, 14 years post-explosion. For a subsolar metallicity consistent with SN 2002ap, we expect a main-sequence (MS) companion present in about two thirds of all stripped-envelope SNe and a compact companion (likely a stripped helium star or a white dwarf/neutron star/black hole) in about 5% of cases. About a quarter of progenitors are single at explosion (originating from initially single stars, mergers, or disrupted systems). All of the latter scenarios require a massive progenitor, inconsistent with earlier studies of SN 2002ap. Our new, deeper upper limits exclude the presence of an MS companion star > 8-10 M., ruling out about 40% of all stripped-envelope SN channels. The most likely scenario for SN 2002ap includes nonconservative binary interaction of a primary star initially. 23 M.. Although unlikely (< 1% of the scenarios), we also discuss the possibility of an exotic reverse merger channel for broadlined Type. Ic events. Finally, we explore how our results depend on the metallicity and the model assumptions and discuss how additional searches for companions can constrain the physics that govern. the evolution of SN progenitors.

Orientador: Antonio Carlos Dias Ângelo / Resumo: Com o intuito de ampliar as fontes de energia por meio de dispositivos eletroquímicos, as células a combustível, o desenvolvimento de eletrocatalisadores que sejam eficientes para a oxidação de combustíveis orgânicos, torna-se primordial. Porém, sabe-se que a eletrocátalise das reações de oxidação de combustíveis orgânicos é certamente, influenciada pelas características geométricas e eletrônicas do material anódico. O presente trabalho estudou a influência do ambiente químico do sítio de adsorção de PtSn sobre a atividade eletroquímica, frente à reação de oxidação de álcoois (etanol, etilenoglicol e glicerol) em meio alcalino. As nanopartículas de PtSn/C foram preparadas sob a configuração de intermetálico ordenado, liga metálica e core-shell suportados em carbono de alta área superficial e caracterizadas por Difração de Raios X, Energia Dispersiva de Raios X, Microscopia Eletrônica de Transmissão e Espectroscopia de Absorção de Raios X. Além disso, os materiais foram avaliados frente à reação de oxidação dos combustíveis pelas técnicas de voltametria cíclica e cronoamperometria. A partir dos resultados foram confirmadas a obtenção das estruturas cristalinas desejadas, na estequiometria 1:1, sendo ainda possível, verificar que o core-shell formado apresentou a configuração Sn@PtSn. O tamanho encontrado para os diferentes eletrocatalisadores PtSn/C, intermetálico ordenado e liga, foram de aproximadamente 2 nm, enquanto que para o core-shell foi o dobro. O material Sn@PtSn apr... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The development of efficient and stable electrocatalysts for organic fuels oxidation reaction is a crucial issue to the application of environmentally friendly electrochemical devices as fuel cells. The electrocatalysis of organic fuels oxidation reactions is surely influenced by the geometric and electronic properties of the anode materials. This work presents the investigation on the influence of the chemical environment around the adsorption surface site in PtSn materials on the alcohols electrooxidation in alkaline medium. PtSn/C nanoparticles were synthesized in three distinct configurations: ordinary alloy, ordered intermetallic and core-shell structure anchored in high surface area carbon support. The obtained materials were characterized by X Ray Diffraction, X Ray Energy Dispersive, Transmission Electron Microscopy and X Ray Absorption Spectroscopy. Furthermore, the synthesized materials were studied as anode materials towards the electrochemical oxidation of organic fuels in alkaline medium by means of the cyclic voltammetry and chornoamperometry techniques. The analysis of the collected data confirmed the aimed geometric structures and the core-shell material Sn@PtSn (ordered), in an atomic ratio 1:1 Pt to Sn. Alloy and ordered intermetallic were found to have about 2 nm diameter of the particle size while Sn@PtSn core-shell was found the double of the size. Core-shell material presented the best performance as used as anode for the electrooxidation of the ethanol,... (Complete abstract click electronic access below) / Doutor

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18592号 / 工博第3953号 / 新制||工||1607(附属図書館) / 31492 / 京都大学大学院工学研究科分子工学専攻 / (主査)教授 田中 庸裕, 教授 田中 勝久, 教授 阿部 竜 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18982号 / 工博第4024号 / 新制||工||1620(附属図書館) / 31933 / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 田中 功, 教授 酒井 明, 教授 邑瀬 邦明 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Perovskite solar cells exhibit outstanding device performance and photovoltaic potential in recent ten years. However, the photoactive layer of the majority of perovskite solar cells with outstanding efficiency currently contains toxic lead. Although perovskite solar cells will be encapsulated prior to application to enhance the device's stability and prevent lead leakage, it is still possible for the devices to be broken or exposed to the environment during actual use. Correspondingly, Pb may enter water or soil through rainfall, posing health risks to humans and other creatures. To prepare perovskite solar cell devices with both high performance and low toxicity, current research concentrates primarily on Pb-Sn hybrid perovskite solar cells as Sn is less toxic than Pb from an environmental standpoint. To intuitively compare the lead leakage of Pb-based perovskite solar cells and Pb-Sn hybrid perovskite solar cells, this study simulated the lead leakage scenario under heavy rainfall conditions using self-prepared, good-performance solar cell devices. Our results indicate that Pb-Sn hybrid perovskite solar cells have less lead leakage than Pb-based perovskite solar cells. The lead leakage concentration of Pb-Sn hybrid perovskite solar cells was 36.8% (in the dripping test) and 41.2% (in the soaking test) lower than that of Pb-based perovskite solar cells.