Well-organized structures of ZnS semiconductor nanocrystals using amphiphilic triblock copolymer aggregates as templates

Ring- and rod-shaped P4VP-b-PS-b-P4VP ( PS, polystyrene; P4VP, poly( 4-vinylpyridine)) triblock copolymer aggregates are used as templates to synthesize ZnS nanocrystals. Herein, PVP serves as both a stabilizing agent and a structure- directing agent. The resulting ZnS nanocrystals could be aligned along the corona of the copolymer aggregates in near-perfect structures through control of both the molar ratio of Zn2+ to P4VP and the reaction time. The diameter of the as-synthesized ZnS layer on the surface of polymer template is approximate 2 - 3 nm. High-resolution transmission electron microscopy images reveal that the ZnS particles are single crystal in a zinc blende structure. This method provides a simple, reproducible route at room temperature to prepare assembled hybrid polymer - semiconductor nanocrystal nanocomposites.

Blends of linear low-density polyethylene and a diblock copolymer of hydrogenated polybutadiene and methyl methacrylate

Blends of linear low-density polyethylene (LLDPE) and a diblock copolymer of hydrogenated polybutadiene and methyl methacrylate [P(HB-b-MMA)] were studied by transimission electron microscope (TEM), differential scanning calorimetry (DSC), and wide angle X-ray diffraction (WAXD). At 10 wt% block copolymer content, block copolymer chains exist as spherical micelles and cylindrical micelles in LLDPE matrix. At 50 wt% block copolymer content, block copolymer chains mainly form cylindrical micelles. The core and corona of micelles consist of PMMA and PHB blocks, respectively. DSC results show that the total enthalpy of crystallization of the blends varies linearly with LLDPE weight percent, indicating no interactions in the crystalline phase. In the blends, no distortion of the unit cell is observed in WAXD tests.

Crystallization of micelles and matrix in dilute diblock copolymer/homopolymer solutions

The crystallization, morphology, and crystalline structure of dilute solid solutions of tetrahydrofuran-methyl methacrylate diblock copolymer (PTHF-b-PMMA) in poly(ethylene oxide) (PEO) and PTHF have been studied with differential scanning calorimetry (DSC), X-ray, and optical microscopy. This study provides a new insight into the crystallization behavior of block copolymers. For the dilute PTHF-b-PMMA/PEO system containing only 2 to 7 wt % of PTHF content, crystallization of the PTHF micellar core was detected both on cooling and on heating. Compared the crystallization of the PTHF in the dilute solutions with that in the pure copolymer, it was found that the crystallizability of the PTHF micellar core in the solution is much greater than that of the dispersed PTHF microdomain in the pure copolymer. The stronger crystallizability in the solution was presumably due to a softened PMMA corona formed in the solution of the copolymer with PEG. However, the "soft" micelles formed in the solution (meaning that the glass transition temperatures (T-g) of the micelle is lower than the T-m of the matrix phase) showed almost no effects on the spherulitic morphology of the PEO component, compared with that of the pure PEO sample. In contrast, significant effects of the micelles with a "hard" PMMA core (meaning that the T-g of the core is higher than the T-m of the PTHF homopolymer) on the nucleation, crystalline structure, and spherulitic morphology were observed for the dilute PTHF-b-PMMA/PTHF system. (C) 1998 John Wiley & Sons, Inc.

SYNTHESIS AND ORIENTATION OF MELAMINEALDEHYDE RESIN CROSS-LINKED POLYMERS

Three kinds of hydroxy-terminated oligomers were synthesized and characterized by IR, DSC and GPC. The oligomers were crosslinked by melaminealdehyde resin. The orientation and relaxation of the poled and crosslinked polymers were studied by UV-Vis spectra. It was shown that polymers had high orientational stability after corona-poling and crosslinking.

Gastroprotective potential of Buddleja scordioides Kunth: Effects into the modulation of antioxidant enzymes and inflammation markers in an in vivo model

Ethnopharmacological relevance: A common plant used to treat several gastric disorders is Buddleja scordioides Kunth,commonly known as salvilla. Aim of thes tudy: To detect inflammatory markers,in order to evaluate the gastroprotective potential of salvilla infusions,as this could have beneficial impact on the population exposed to gastric ulcers and colitis. Materials and methods: The present work attempted infusions were prepared with B. scordioides (1% w/w) lyophilized and stored.Total phenolic content and GC–MS analysis were performed. Wistar rats were divided into five groups a negative vehicle control,an indomethacin group,and three experimental groups,named preventive,curative,and suppressive. All rats were sacrificed under deep ether anesthesia(6h)after the last oral administration of indomethacin/infusion.The rat stomachs were promptly excised,weighed,and chilled in ice-cold and 0.9%NaCl.Histological analysis,nitrites quantification and immunodetection assays were done. Results: B.scordioides infusions markedly reduced the visible hemorrhagic lesions induced byindomethacin in rat stomachs,also showed down-regulation of COX2, IL-8 and TNFα and up-regulation of COX-1with a moderate down-regulation of NFkB and lower amount of nitrites.However,this behavior was dependent on the treatment,showing most down-regulation of COX-2,TNFα and IL-8 in the curative treatment;more down-regulation of NF-kB in the preventive treatment;and more up-regulation of COX-1 for the suppressor and preventive treatments. Conclusion: The anti-inflammatory potential of B. scordioides infusions could be related with the presence of polyphenols as quercetin in the infusion and how this one is consumed.

The magnetic structure of a coronal X-ray bright point

Brown, D.S., Parnell, C.E., Deluca, E., McMullen, R. and Golub, L., 2001, The magnetic structure of a coronal X-ray bright point, Solar Physics, 201, 305-321.

A Topological Analysis of the Magnetic Breakout Model for an Eruptive Solar Flare

Maclean, R., Beveridge, C., Longcope, D.W., Brown, D.S. and Priest, E.R., 2005, A topological analysis of the magnetic breakout model for an eruptive solar flare, Proc. Roy. Soc., 461, 2099-2120. Sponsorship: PPARC/STFC

The Depiction of Coronal Structure in White-Light Images

Morgan, Huw, Habbal, S.R., Woo, R., (2006) 'The Depiction of Coronal Structure in White-Light Images', Solar Physics 236(2) pp.263-272 RAE2008

An empirical 3D model of the large-scale coronal structure based on the distribution of H? filaments on the solar disk

Morgan, H.; Habbal, S. R., An empirical 3D model of the large-scale coronal structure based on the distribution of H? filaments on the solar disk, Astronomy and Astrophysics, Volume 464, Issue 1, March II 2007, pp.357-365

Transition region, coronal heating and the fast solar wind

Li, Xing, 'Transition region, coronal heating and the fast solar wind', Astronomy and Astrophysics (2003) 406 pp.345-356 RAE2008

The Impact of Sunspots on the Interpretation of Coronal Observations of the O VI Doublet

Morgan, Huw; Habbal, S. R., 'The impact of sunspots on the interpretation of coronal observations of the OVI doublet', The Astrophysical Journal (2005) 630(2) pp.L189-L192 RAE2008

La libertad condicional antes y después de la LO 1/2015, de 30 de marzo

En el presente trabajo he efectuado un estudio sobre la libertad condicional en nuestro país. He analizado los importantes cambios que ha sufrido esta institución, que ha pasado de constituir una parte o modalidad del cumplimiento de la pena de prisión para llegar a ser, tras la reforma de la LO 1/2015 de 30 de marzo, una modalidad de suspensión de la ejecución de la pena de prisión. Estudio las distintas modalidades de libertad condicional reguladas, las exigencias establecidas durante el período de libertad condicional y la revocación de la misma y sus consecuencias

Antropoloxía e literatura oral

A proposta realizada neste traballo fai de altovolante dalgunhas reflexións que creo fundamentais para seguir camiño na investigación da literatura oral. A miña perspectiva é a da antropoloxía sociocultural, pero afecta nun sentido máis amplo ao conxunto das disciplinas sociais e humanísticas que abordan o tema da literatura oral e da oralidade en xeral. É evidente que a literatura aporta datos sobre a organización social, o estilo de vida e a Cultura dunha sociedade no pasado e no presente (1). En particular a literatura oral, é dicir, a que se transmite oralmente aínda que ás veces a encontremos escrita, é un vector privilexiado para captar os imaxinarios colectivos do grupo humano que a crea, os seus valores, as súas moralidades e crenzas. The paper presents some lines of thought considered to be fundamental in the study of oral literature. The perspective followed is one marked by socio/cultural anthropology, but one that is also related to all of those Social Sciences and Humanities that analyse oral traditions. Literature gives us data on social organization, on the life style and culture of a social group, both past and present. Oral literature, in particular, is a extremely suitable vehicle for reaching the collective imaginary of the group that creates it. (1) Fribourg, J.(1995): "Literatura oral y antropología", en Lisón Tolosana, C. (comp.): Antropología y Literatura. Zaragoza: Gobierno de Aragón, p. 37.

Reabilitação fixa aparafusada Vs. reabilitação fixa cimentada

Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária

Visita Primera Dama Nohra Puyana de Pastrana a Expoartesanías 2000.

6 hojas : ilustraciones, fotografías.