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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.
1

Word Syntax of Nominal Compounds: Internal and Aphasiological Evidence from Turkish

Tat, Deniz January 2013 (has links)
This dissertation is an analysis of two types of nominal compounds in Turkish, primary compounds and synthetic compounds within the framework of Distributed Morphology. A nominal primary compound is formed by two nouns, and its meaning is largely determined by world knowledge. A synthetic compound, on the other hand, is formed by a noun and a derverbal noun, such that the former is a true argument of the latter. The meaning of such compounds is always compositional. In many languages, the structural difference between these two types of compounds is not immediately observable. However, in Turkish, a primary compound would be obligatorily marked with the compound marker, -(s)I(n) while a synthetic compound would never be marked as such. In this dissertation, I claim that primary compounds in Turkish are underlyingly possessive phrases, a claim that has been previously made by several others. My analysis differs from those previous analyses in that it maintains that -(s)I(n) figures in a morphological component that follows syntax but precedes PF. Such a post-syntactic analysis has a number of advantages as it can account for a wide range of descriptive observations about the behavior of -(s)I(n). I claim that -(s)I(n) and an agreement marker never form a sequence at any stage in the grammar. I test this claim in an experiment conducted with Turkish-speaking individuals with aphasia, and show that only a vanishingly rare number of -(s)I(n)-agreement sequences are attested in aphasic speech. My analysis of synthetic compounds in Turkish is based on three types of nominalizers and the types of categories they can select. I show that only event-denoting nominals can form true synthetic compounds. I also show that nominals that are derived directly from roots can never form true synthetic compounds, which casts doubts on roots as projecting categories. I also consider a third group of seemingly synthetic compounds, which have an overt complex verbal stem, and yet, fail to derive true synthetic compounds. Following Marantz (2013), I claim that such pseudo-synthetic compounds, in fact, have semantically null verbalizing morphemes, and therefore, the root and the nominalizing head are semantically adjacent at LF.
2

Syntheses and the Structures of Polymethylpolycyclic and Polycyclic "Cage" Molecules

Zhao, Dalian 05 1900 (has links)
The structures of Diels-Alder cycloaddition of cyclopentadiene to 2,6-dimethyl-p-benzoquinone and methylcyclopentadiene to 2,6-dimethyl-p-benzoquinone were assigned by analysis of 1-D and 2-D proton and carbon-13 NMR spectra. The structures of the cycloadduct of methylcyclopentadiene to 2,6-dimethyl-p-benzoquinone and that of the corresponding intramolecular [2+2] photocyclization product were also obtained by single crystal X-ray structural analysis. As the second part of the study, a new polycyclic "cage" molecule, a substituted trishomocubane isomer, was synthesized. In this synthesis, reductive bond cleavage followed by Dieckmann condensation was employed. Wolff-Kishner reduction then was used to convert a β-keto ester "cage" molecule to the corresponding carboxylic acid. A compound that possesses twofold symmetry was isolated from reaction product mixture. The structure of this compound has been established by single crystal X-ray crystallography.
3

Antimycobacterial activity of synthetic compounds isolated from South African medicinal plants against mycobacterium tuberculosis

Ledwaba, Elizabeth Ramadimetsa 11 1900 (has links)
M. Tech. (Department of Health Sciences, Faculty of Applied and Computer Sciences), Vaal University of Technology. / Tuberculosis (TB) remains one of the most difficult infectious diseases to control in the world today. The disease spreads easily in overcrowded, badly ventilated places and among people who are undernourished. Trends in the incidence of TB together with the development of multi-drug (MDR-TB) and extensively drug resistant (XDR-TB) strains of TB raises the need to intensify the search for more efficient drugs to combat this disease. Herbal remedies used in traditional medicine provide an interesting and largely unexplored source for the discovery of potentially new drugs for infections such as TB. The aim of the study was to evaluate the in vitro antimycobacterial activity of synthesized compounds from medicinal plants against Mycobacterium tuberculosis (M. tuberculosis). About 40 synthesized compounds isolated from South African medicinal plants were screened against H37RV using microplate alamar blue assay (MABA). Identified active compounds were screened against resistant strains of M. tuberculosis (MDR, XDR and pre-XDR) and sensitive clinical isolates of TB. Cytotoxicity and synergistic drug combination studies were done on active compounds to validate their toxicity and synergy levels. Cytotoxicity was done by sulforhodamine assay (SRB) against the C2C12 cell line. Only six compounds showed activity against M. tuberculosis with minimum inhibitory concentration (MIC) below 10μg/ml. The results obtained indicated that the cytotoxicity effects of the three compounds on C2C12 cells demonstrated marginal toxicity except for MVB 282/61215 which showed a high toxicity at the lowest concentration of 0.156μg/ml with over 100% viable cells at the highest concentration (5μg/ml). MVB 282/61271 had the highest percentage cell viability (65%) at the lowest concentration. Only two compounds had a higher potency evoking a bigger response at low concentrations with treated cells still viable after 3 days of incubation with the compound which was comparable with the treatment of isoniazid (INH). Synergistic activity of the six compounds was less in INH combination as compared to the rifampicin’s (RIF) combination. The results demonstrated that the synergistic interaction between the compounds and RIF could the antituberculosis acitivity. In conclusion the synergistic effects with RIF translate to lower dosing requirements of the compounds and the potential to combat multidrug resistant TB. In deed there is no doubt that natural products, with their range of interesting chemical structures and powerful antimycobacterial effects are certain to remain important participants in the development of new generations of antimycobacterial drugs.

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