Nanomaterials such as gold nanowires and gold nanoparticles were self-assembled with several peptides derived from betaamyloid peptide. The peptides propensity to form fibrilar structures was exploited. The products obtained by aggregation of the peptides with the nano materials were studied using HPLC, UV-vis spectroscopy, TEM and optical light microscopy.

Abstract Diamond is nowadays regarded as a potential semiconductor material of the future, due to its extreme and unique properties. Some of these properties, in- clude its high hardness, highest breakdown ¯eld, high Debye temperature, high thermal conductivity, high hole and electron mobilities, large bandgap and op- tical transparency, among others. These properties make diamond suitable for high-temperature, high-speed and high-power electronic applicatons, as well as in other applications. However, defects associated with ion implantation have been shown to make it rather di±cult to obtain n-type doping in diamond. As such, an understanding of the nature of defects produced during ion implanta- tion of diamond remains a subject of great importance, if not essential, for the optimization of high-temperature, high-power electronic applications in partic- ular. In this respect, this study investigates the nature of the radiation damage generated within the collision cascades of multi-implantations of carbon ions in high-pressure, high-temperature single-crystal synthetic type Ib diamond, spread over a range of energies (50-150keV) and doses. This is achieved by means of the cold-implantation-rapid-annealing (CIRA) routine, and the anal- ysis of damage caused was done by using cross sectional transmission electron microscopy techniques. More precisely, the modes used to achieve this are the bright ¯eld transmission electron microscopy (BFTEM) coupled with selected area di®raction or SAD. At low dose implantation or at sub-critical implantation doses (2.5x1015 ions/cm2), it was found that the ion-damaged diamond layer consists of some threading dislocations, not homogeneously distributed which propagate from the surface into the ion-damaged diamond. In contrast to the sub-critical implantation doses , it was found that at very high implantation doses (7.0x1015 ions/cm2), i.e., above the critical dose (where diamond transforms to graphite upon annealing), the damaged diamond layer had some unconventional defect features close to the implanted surface.

The Rajapalot gold-cobalt project in northern Finland is an exciting, relatively new discovery, still being explored with hopes to start mining in the future. The area was found by a IP/Resistivity survey in 2013. Extensive geophysical follow-up surveys have delineated several electromagnetic targets, one of which, named Raja, is the target anomaly this master thesis is built upon. A TEM survey was carried out during late August to early September 2018. The data collected was analyzed, processed and later modelled in Maxwell using Leroi, a CSIRO module. Three separate models are produced with one, two, and three plates respectively. The result is compared to existing VTEM and resistivity models. / Rajapalot guld-kobolt-projektet i norra Finland är en spännande, relativt ny upptäckt som fortfarande undersöks med hopp om att starta gruvbrytning i framtiden. Området upptäcktes via en IP/Resistivitets-undersökning under 2013. Omfattande geofysiska undersökningar har avgränsat flera elektromagnetiska anomalier, varav en, döpt Raja, är den anomali som den här masteruppsatsen är uppbyggd kring. En TEM-undersökning utfördes under slutet av augusti, början av september 2018. Insamlade data analyserades, bearbetades och modellerades senare i Maxwell med hjälp av Leroi, en insticksmodul från CSIRO. Tre separata modeller togs fram med respektive, en, två, och tre plattor. Resultatet jämfördes mot befintliga VTEM-, och resistivitetsmodeller.

A detailed row by row investigation of major lateral tooth cusp mineralisation, together with the concomitant development of the superior epithelial tissue surrounding the teeth of the chiton Acanthopleura hirtosa has been undertaken using a combination of light microscopy, and scanning and transmission electron microscopy. A holistic approach has been adopted that encompasses observations over a range of spatial scales, from whole radula mineralisation processes to those occurring within individual tooth cusps at various stages of development. In addition, mineralisation in radulae from freshly collected animals has been compared to that of animals maintained for extensive periods within a newly developed iron limited system, which restricts radula mineralisation without impeding the formation of the organic matrix. An evaluation of the iron limitation technique has revealed that maintaining specimens of A. hirtosa within an iron poor environment results in a significant departure from the normal pattern of mineralisation in these animals. As a consequence of iron limitation, there is an obvious increase in the number of unmineralised tooth rows in addition to associated alterations in structure and composition at all stages of tooth development. In normal specimens of A. hirtosa, the onset of mineralisation in the tooth cusps occurs following the prior accumulation of iron at the junction zone and the sudden accumulation of iron containing granules in the cusp epithelium at tooth row 13. The superior epithelium surrounding the tooth cusps undergoes a series of developmental changes leading up to, and following, the onset of mineralisation. In particular, the abundance of mitochondria within the apical cusp epithelium increases, presumably in order to provide the ideal conditions of pH, and thus solubility, needed for the supersaturation of iron and its nucleation at row 13. Once mineralisation has commenced, the microvilli attached to the cusps develop rapidly, and are suggested to do so in order to facilitate the transport of iron, and thereby ensure that a high concentration gradient of this element into the cusps is maintained. The delivery of iron into the cusps occurs from two fronts, the first from the superior epithelium via the posterior surface, and the second from the junction zone via an internal pathway situated along the lepidocrocite boundary between the magnetite and core regions of the tooth. The existence of a plume of elements between this internal mineralisation pathway and the junction zone, provides the first direct evidence that the junction zone is involved in the storage and release of elements for cusp mineralisation. Data from iron limited radulae also indicate that iron continues to be deposited at the junction zone in preference to the superior epithelium or cusps, despite the disruption of mineralisation, highlighting the importance of this region in the mineralisation process. Iron reinstatement experiments have also shown that the internal pathways of iron delivery within the organic matrix remain viable, despite prolonged periods of iron limitation. In addition, the reinstatement of iron has revealed that the plumes, situated between the junction zone and internal mineralising pathway of the cusp, stem from the centre of the plate like junction zone, directly above the stylus canal, a tube like cavity situated within the styli of each major lateral tooth. An in depth study of the stylus canal has revealed that cells within the canal are remarkably similar to those of the epithelium surrounding the cusps, suggesting that this structure may also be involved in the delivery of ions to the junction zone. The stylus canal is shown to be present in the major lateral tooth cusps of 38 chiton species distributed worldwide, and is therefore likely to be a feature common to all chitons. The presence of the canal, and indeed its absence from the bases of all remaining non iron mineralised teeth, irrespective of chiton species, also points strongly to a functional relationship between the stylus canal and tooth cusp mineralisation.

Coatings are often used on critical components in machines and engines to reduce wear and to provide low friction in order to reduce energy losses and the environmental impact. A triboactive coating not only provides this desired performance, it also actively maintains the low friction by a structural or chemical change in a very thin top layer of these already micrometer thin coatings. This so-called tribofilm is often 5-50 nm thick and can be formed either from the coating itself or by a reaction with the counter surface or the surrounding atmosphere, i.e. gas, fuel, oil, etc. The tribofilm will maintain the wanted performance for as long as the system is not chemically disturbed. This thesis provides a detailed overview of the functionality of triboactive low-friction coatings, in many different systems. The majority of the tribofilms discussed, formed in very different environments, are built up by tungsten disulfide (WS2), which is a material similar to graphite, with a lamellar structure where strongly bonded atomic planes may slip over each other almost without resistance. The major difference is that WS2 is an intrinsically triboactive material, while graphite is not. However, graphite and other carbon-based materials can be made triboactive in certain atmospheres or by addition of other elements, such as hydrogen. The remarkable affinity and driving force to form such WS2 low-friction tribofilms, regardless of the initial states of the sulfur and tungsten, and even when the forming elements are present only at ppm levels, is a recurrent observation in the thesis. Addition of an alloying element to sputtered coatings of WS2 can improve its mechanical and frictional properties significantly. Several promising attempts have been made to find good candidates, out of which a few important ones are investigated in this thesis. Their achievable potential in friction reductions is demonstrated. By reducing friction, energy losses can be avoided, which also results in lower particle and exhaust emissions, which directly reduces the environmental impact. Triboactive coatings are shown to be a promising route to significantly improve tribological applications and allow more environmental friendly and energy efficient vehicles.

Durant la transició Epiteli-Mesènquima (TEM), el factor de transcripció Snail reprimeix la transcripció de l'E-cadherina unint-se a les caixes E presents en el promotor d'aquest gen.Les cèl·lules que expressen Snail presenten un fenotip fibroblastoide amb pocs contactes cel·lulars: els gens epitelials són reprimits (E-cadherina, MUC1 i VDR) i els gens mesenquimals són induïts (Zeb1).La sobre-expressió de Snail en varies línies cel·lulars donarà lloc a un augment en els nivells de RNA i de l'activitat del promotor de Zeb1. A més, Zeb1 reprimeix l'E-cadherina i MUC1.Estàvem interessats en el mecanisme de repressió i inducció de gens per Snail. Snail necessita de HDAC per a realitzar el seu mecanisme de repressió. A més, es va estudiar el mecanisme de inducció del promotor de Zeb1. El promotor de Zeb1 era activat en línies cel·lulars que responien a estímuls de TEM, com la sobre-expressió de ILK, de l' oncogen Ha-Ras o de la cPK-Ca. Finalment es va descriure que el promotor de Zeb1 responia a NF-kB, b-catenina/TCF4 i Twist. / During Epithelial mesenchymal transition (EMT), the transcriptional factor Snail represses E-cadherin transcription by binding to E-box sequence of the E-cadherin promoter. Cells expressing Snail presented a scattered flattened phenotype with low intercellular contacts: epithelial gene are repressed (E-cadherin, VDR and Muc-1) and mesenchymal genes are induced (Zeb1). Snail overexpression in several lines raised ZEB1 RNA levels and increased the activity of ZEB1 promoter. ZEB1 repressed E-cadherin and MUC1.We were interested in Snail repression and induction mechanism. We analysed whether Snail needs other proteins for its repression function and we found HDAC such as partners in Snail repression. In addition, we are studying its activation activity upon Zeb1 promoter. The human Zeb1 promoter was activated in cell lines that respond to agents that induce mesenchymal phenotype, as overexpression of integrin-linked kinase (ILK) or oncogenes such as Ha-ras or cPK-Ca. Moreover, Zeb1 promoter was activated by different proteins implicated in EMT, such as, NF-kB, b-catenin/TCF4 and Twist.

¡@¡@Igneous activity of Taiwan in Miocene mainly were concentrated in the area north of Miaoli. Nanman is one of the basalt in southern of Taiwan that had been studied by OM, XRD, SEM/EDS and TEM. The rock type is alkali basalt with phenocryst of augite and olivine. The primary minerals include olivine + augite + plagioclase + Anorthoclase + apatite +titanomagnetite + illmenite, and secondary minerals are chlorite + smectite + calcite ¡Ó gypsum.Alteration of Nanman basalt was take placed in mixture and crack of olivine, other minerals are almost fresh. The main replacement are chloritic minerals shown five occurrence types : (1) replaced mixture, (2) vein center of olivine crack, (3) vien of olivine, (4) fibrous and (5) mica-like clay between vein and residual olivine. Each types has clear grain boundary. It¡¦s mean they are not gradual. (4) and (5) are smectite with anomaly composititon. It cause by lack of Al resource, and smectite occurred far from the crack that element do not easily move. Thus, smectite replaced olivine often showed Al-poor and excess Mg. Si/(Si+Al) and Fe/(Fe+Mg) in smectite is positive correlation. This may be considered the moving ability of elements. Composition of (1), (2) and (3) are chlorite/smectite. However there is no observed mixed-layer minerals in XRD. According to TEM , they are chlorite + smectite. Chlorite within abundant of dehydrated cracks could be a evidence of smectite. Because of mixed chlorite and smectite, the correlation between Si/(Si+Al) and Fe/(Fe+Mg) is negative. Different occurrences lead to different mineral, suggest water/rock ratio is an important control factor. High rock/water ratio trend to form chlorite, and low rock/water ratio prefer to form smectite. According to all the results, the steps of altered olivine are first forming chlorite at mixture and olivine cracks. Then, the residual olivine becomes smectite with poor Al and excess Mg, when the rock was cooling down.

Iridovirus infections have led to serious economic loss in the aquaculture industry in Kaohsiung County as well as the whole Southern Taiwan region. Identified susceptible host species in this region includes hybrid grouper (Epinephelus hybrid), giant seaperch (Lates calcarifer), largemouth bass (Micropterum salmoides), king grouper (Epinephelus lanceolatus), spotted butter fish (Scatophagus argus), yellow-wax pomfrat (Trachinotus blochii), goldlined seabream (Sparus sarba), humpback grouper (Chromileptes altivelis), Mangrove red snapper (Lutjanus argentimaculatus). In this study, a diagnostic PCR primer pair CY15n-F/CY15nR, and its nested primer pair RY16-F/RY16-R, were designed and applied to amplify virus-specific products of 1339 bp and 305 bp, respectively. This primer set did not amplify products from lymphocystis disease virus, largemouth bass virus, or healthy control fish DNA. This sensitive technique can detect the presence of 50 fg plasmid with viral DNA insert in the presence of 100 ng/£gl host DNA, or 0.05 fg DNA from infected fish. Comparing sequences of CY15 fragment, ATPase gene, predicted major capsid protein and partial DNA polymerase genes among iridoviruses, it is suggested that the viruses found in this area should be classified as the Megalocytivirus of Iridoviridae. These viruses are clearly different from the Ranavirus, another fish-pathogenic iridovirus. Those iridoviruses can be classified into two genotypes: the CY630 type, which is the Taiwan grouper iridovirus; and the CY113 type, which is similar to red seabream iridovirus (RSIV). The identity in CY15 fragment sequences is about 91%. Microscopically, enlarged cells can be found in organs of infected fishes. They appear in the spleen, head kidney, and trunk kidney in infected groupers. The enlarged cells may be relocated from other organs. In giant seaperch, the enlarged cells appeared in the above mentioned organs, and also in the digestive tract and the heart. Two kinds of the enlarged cells in grouper can be distinguished by their H&E staining properties: the basophilic and the eosinophilic enlarged cells. The result from in situ hybridization and electron microscopy suggest that the viruses only appear in the basophilic enlarged cells. Both nucleus and cell volume increase in basophilic enlarged cells, while only the cell volume increases in the eosinophilic enlarged cells. The viruses appeared first in the nuclei of the basophilic enlarged cells, after the mid-phase of the infection they distributed into the whole cells. Judging from the results of phagocytosis, acid phosphatase activity and the ultrastructure of infected cells, it is suggested that this target cell is macrophage or monocyte. The viral capsid is assembled in the viromatrix, and the virogenic stroma can be either ring-shped or disc-shaped. The diameter of mature virus is 120-130 nm from side to side, or 160-170 nm from apex to apex. The electron-lucent space between the capsid and the envelope is about 20-50 nm. The virus particles can be found in (1) lysosome-like vesicles in the cytoplasm, if the host cell still has its nucleus; or (2) the viromatrix, When the host nucleus is dissolved or only has some vestige nuclear membrane left.

ABSTRACT For the generation of broadband tunability over 1300 nm to 1600 nm range in optical communications, Cr4+ ions have been demonstrated in a number of hosts including Cr4+:forsterite, Cr4+:Y2SiO5, and Cr4+:YAG. Since YAG is a cubic crystal with Ia-3d space group, its excellent thermal and optical properties has drawn extensive studies. In recent years, various modes of operation using Cr4+:YAG as laser gain medium have been achieved since the first tunable CW laser of Cr4+:YAG bulk gain medium was demonstrated by Shestakov, et al in 1988. Experimentally, the Cr4+:YAG crystal fiber was grown by the laser-heated pedestal growth (LHPG) method which provides outstanding crystal quality and can easily change growth conditions, such as growth speed and core diameter. A double cladding technique was developed with pure YAG, silica/YAG mixture, and pure silica as the core, inner cladding, and outer cladding, respectively. The smallest core diameter we achieved is 11 mm. In this thesis, the fabrication process of the Cr4+:YAG crystal fiber laser involving crystal fiber growth, sample preparation, and coating design will be presented in detail. In order to understand the relation between the microstructure of Cr4+:YAG crystal fibers and the growth conditions, high-resolution transmission electron microscopy (HRTEM) was employed, which reveals the nano-scale information in the core region, the inner-outer cladding interface, and the mechanism of inter-diffusion process during growth. In addition, the thesis also describes the specimen preparation procedures of crystal fibers for the HRTEM analysis. Furthermore, quantitative analysis of Cr4+:YAG crystal fiber was employed by electron-probe micro-analyzer (EPMA) and energy dispersive X-ray spectrometer (EDX), showing accurate characterization of the constitute elements and concentrations. The comparison of Cr4+ fluorescence and dopant concentration of CaO and Cr2O3 will also be presented in this thesis.

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