Polymeric membranes typically possess a broad pore-size distribution that leads to much lower selectivity in molecular and ionic separation when compared to membranes made of crystalline porous materials; however, they are highly desirable because of their easy processability and low cost. Recently, a novel type of conjugated microporous polymers (CMPs) has shown uniform pore size and high porosity. However, their brittleness nature has prevented them from preparing robust membranes and using in pressure-driven membrane processes. In this dissertation, we demonstrate the fabrication of robust polycarbazole-type conjugated microporous polymer membranes using an easy to scale-up electropolymerization strategy. The mechanical properties of the CMP membranes were greatly enhanced based on membrane structure optimization and molecular design. The prepared membranes exhibited high uniform sub-nanometer pores and a precisely tunable membrane thickness and properties, yielding high molecular/ionic sieving performance. In addition, using the co-electropolymerization method, the CMP membranes achieve dual softness and functionalization adjustments. The membrane structure comprises rigid monomers to inherit the structural uniformity and flexible and charged monomers to enhance mechanical flexibility and improve ion selectivity by combining the precise size sieving and the Donnan effect. The dual-adjustments result in the further enhancement of the CMP membranes in ionic sieving performance. Inspired by light-gated ion channels in living cells, we further develop a smart artificial light-gated ion channel membrane. The prepared CMP membranes, based on a conjugated microporous polymer (CMP) functionalized with azobenzene and precisely designed on the molecular level, show uniform pore channels and highly sensitive light-switchable response. The photoisomerization results in reversible geometric changes in pore channel size, leading to “on-off-on” light-control over the channels, which results in light-gated ion transport across the smart membrane. The softness adjustment, functionalization adjustment to CMP membranes, and the design of smart CMP membranes provide potential applications for this important category of polymer materials in the membrane field.

No description available.

Cyclic sieving phenomenon (CSP) is a generalization by Reiner, Stanton, White of Stembridge's q=-1 phenomenon. When CSP is exhibited, orbits of a cyclic action on combinatorial objects show a nice structure and their sizes can be encoded by one polynomial. In this thesis we study various proofs of a very interesting cyclic sieving phenomenon, that jeu-de-taquin promotion on rectangular Young tableaux exhibits CSP. The first proof was obtained by Rhoades, who used Kazhdan-Lusztig representation. Purbhoo's proof uses Wronski map to equate tableaux with points in the fibre of the map. Finally, we consider Petersen, Pylyavskyy, Rhoades's proof on 2 and 3 row tableaux by bijecting the promotion of tableaux to rotation of webs. This thesis also propose a combinatorial approach to prove the CSP for square tableaux. A variation of jeu-de-taquin move yields a way to count square tableaux which has minimal orbit under promotion. These tableaux are then in bijection to permutations. We consider how this can be generalized.

Toxic metals contaminate soil worldwide and thus serve as sever environmental threat. Therefore the purposes of this study were to investigate in which soil fractions that different heavy metals (Fe, As, Cu, Zn and Pb) could be found in contaminated soils and if it is possible to use sieving as a method for decontamination. Soil samples were collected from three different locations, the Nasa silver mine, the Blaiken-mine and Svalget environmental station. The samples were oven dried and later on sieved into six different fractions 8mm, 4 mm, 0.5 mm, 0.250mm, 0.063 mm and <0.063 mm. The fractions 4 mm, 0.5 mm and <0.063 mm from each location were analyzed in an x-ray fluorescence detector. The results showed that in general the smallest fractions contained the highest concentration of heavy metals which was very clear for Pb where 5 out of 6 samples had the highest concentration in the smallest fraction. The highest concentration of Cu (1147 ppm) and Zn (1117 ppm) were found in the smallest fraction in samples from the location Svalget. The highest concentration of Pb (10042 ppm) was also found in the smallest fraction in samples from Blaiken. In similarity the highest concentration of As (13305 ppm) was found in the smallest fraction in samples from the Nasa mine. However, in most samples the difference between the smallest fractions and the coarser material was small. Sieving may therefore not be the best way to decontaminate soil because even the larger fractions contained high concentrations of heavy metals.

Cyclic sieving phenomenon (CSP) is a generalization by Reiner, Stanton, White of Stembridge's q=-1 phenomenon. When CSP is exhibited, orbits of a cyclic action on combinatorial objects show a nice structure and their sizes can be encoded by one polynomial. In this thesis we study various proofs of a very interesting cyclic sieving phenomenon, that jeu-de-taquin promotion on rectangular Young tableaux exhibits CSP. The first proof was obtained by Rhoades, who used Kazhdan-Lusztig representation. Purbhoo's proof uses Wronski map to equate tableaux with points in the fibre of the map. Finally, we consider Petersen, Pylyavskyy, Rhoades's proof on 2 and 3 row tableaux by bijecting the promotion of tableaux to rotation of webs. This thesis also propose a combinatorial approach to prove the CSP for square tableaux. A variation of jeu-de-taquin move yields a way to count square tableaux which has minimal orbit under promotion. These tableaux are then in bijection to permutations. We consider how this can be generalized.

No description available.

No description available.

The development of new and effective drugs is strongly affected by the need to identify drug targets and to reduce side effects. Unfortunately, resolving these issues depends partially on a broad and thorough understanding of the biological function of many proteins, and the experimental determination of protein function is expensive and time consuming. In response to this problem, algorithms for computational function prediction have been designed to expand experimental impact by finding proteins with predictably similar function, mapping experimental knowledge onto very similar, unstudied proteins. This thesis seeks to develop one method that can identify useful geometric and chemical similarities between well studied and unstudied proteins. Our approach is to identify matches of geometric and chemical similarity between motifs , representing known functional sites, and substructures of functionally uncharacterized proteins ( targets ). It is commonly hypothesized that the existence of a match could imply that the target contains an active site similar to the motif. We have designed the MASH ( M atch A ugmentation with S tatistical H ypothesis Testing) pipeline, a software tool for computing matches. MASH is the first method to match point-based motifs, developed in earlier work, that represent functional sites as points in space with ranked priorities and alternative chemical labels. MASH is also first to match cavity-aware motifs, a novel contribution of this work, that extend point-based motifs with volumetric information describing active clefts critical to protein function. Controlled experiments demonstrate that matches for both types of motifs can identify cognate active sites. However, motifs can also identify matches to functionally unrelated proteins. For this reason, we developed M otif Profiling (MP), the first method for motif refinement that reduces geometric similarity to functionally unre lated proteins. MP is implemented in two forms: Geometric Sieving (GS) refines point-based motifs and Cavity Scaling (CS) refines cavity-aware motifs. Controlled experimentation demonstrates that GS and CS identify motif refinements that have more matches to functionally related proteins and less matches to functionally unrelated proteins. This thesis demonstrates the importance of computational tools for matching and refining motifs, emphasizing the applicability of large-scale geometric and statistical analysis for functional annotation. / National Science Foundation, National Library of Medicine, AMD, Cray

Diss. (sammanfattning) Umeå : Sveriges lantbruksuniv., 2009. / Härtill 6 uppsatser.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20263号 / 医博第4222号 / 新制||医||1020(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 長船 健二, 教授 小川 修, 教授 福原 俊一 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM