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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

Isolation and Characterization of Active Ingredients from Nigella Sativa for Antibacterial Screening.

Kahsai, Alem Welderufael 16 August 2002 (has links) (PDF)
In the past two decades, few reports have confirmed the various antibacterial activities of total extract from the seeds of Nigella sativa (Black cumin). In attempts to identify the active ingredients in this extract, the seeds were extracted with hexane. The volatile oil obtained from the crude extract was shown to contain at least three distinct compounds, thymoquinone, p-cymene, and α-pinene, as confirmed by GC/MS and NMR spectroscopy. While p-cymene and α-pinene showed no antibacterial activities, thymoquinone, exhibited remarkable inhibition of the growth of various strains of bacteria. For instance, the IC50 and the Minimal Inhibitory Concentration (MIC) for thymoquinone were found to be 1.31 μg/mL and 3.6 μg/mL respectively, when tested against the gram-positive bacteria, S. aureus. It is also found that thymoquinone significantly inhibites the protein and RNA synthesis in S. aureus.
2

Amelioration of the chronic relapsing experimental allergic encephalomyelitis using thymoquinone

Waris, Muhammad Hashim 18 April 2011
Axonal damage, demyelination and inflammation of the central nervous system are the major pathological features of multiple sclerosis (MS). MS is thought to be due to an abnormal T cell mediated immune response. Oxidative stress plays an important role in the advancement of MS. The reduced glutathione (GSH) has very important role in the management of oxidative stress. In our experiment we used Experimental autoimmune encephalomyelitis (EAE) animal model that mimic human MS and tested the effect of Thymoquinone (TQ) a constituent of oil of Nigella Sativa also known as black seed. Thirty female mice strain C57BL/6J between 6 to 12 weeks of age were placed into 3 groups of 10 and MOG was used subcutaneously (s.c) to induce EAE. Group A, the control group. Group B, received MOG (s.c) and TQ intraperiotoneally (i.p) from day 1 till day 50. Group C, received MOG (s.c) and TQ (i.p) was given on the appearance of first sign and symptoms of Chronic relapsing EAE (CR-EAE). All Mice were examined daily for behavioral deficits and all euthanized and sacrificed on day 50. In this study we found mice belonging to group C (EAE with TQ treatment after the appearance of chronic symptoms) were observed to have the highest mean clinical scores in both the acute and chronic phases of EAE with symptom reduction following the TQ injections. Group B (which received daily TQ injections) had decreased symptoms compared to Group A and C. Glutathione level dropped significantly in the control group (p < 0.05) and increased (p > 0.05) in groups B and C mice who received TQ injections. We also noted that EAE clinical signs correlated well with the extent of perivascular lymphocyte infiltrate compared with normal histology following TQ injections. Our results indicate that TQ, due to its anti-oxidant effects is almost 80% preventive and 50% curative in CR-EAE. These results could assist further studies on the mechanism of the action of TQ in CR-EAE and on the possibility of treating the chronic- relapsing phase of human multiple sclerosis. It seems within the realm of possibility that TQ may be as, if not more, therapeutically efficacious as interferon â and glatiramer acetate.
3

Amelioration of the chronic relapsing experimental allergic encephalomyelitis using thymoquinone

Waris, Muhammad Hashim 18 April 2011 (has links)
Axonal damage, demyelination and inflammation of the central nervous system are the major pathological features of multiple sclerosis (MS). MS is thought to be due to an abnormal T cell mediated immune response. Oxidative stress plays an important role in the advancement of MS. The reduced glutathione (GSH) has very important role in the management of oxidative stress. In our experiment we used Experimental autoimmune encephalomyelitis (EAE) animal model that mimic human MS and tested the effect of Thymoquinone (TQ) a constituent of oil of Nigella Sativa also known as black seed. Thirty female mice strain C57BL/6J between 6 to 12 weeks of age were placed into 3 groups of 10 and MOG was used subcutaneously (s.c) to induce EAE. Group A, the control group. Group B, received MOG (s.c) and TQ intraperiotoneally (i.p) from day 1 till day 50. Group C, received MOG (s.c) and TQ (i.p) was given on the appearance of first sign and symptoms of Chronic relapsing EAE (CR-EAE). All Mice were examined daily for behavioral deficits and all euthanized and sacrificed on day 50. In this study we found mice belonging to group C (EAE with TQ treatment after the appearance of chronic symptoms) were observed to have the highest mean clinical scores in both the acute and chronic phases of EAE with symptom reduction following the TQ injections. Group B (which received daily TQ injections) had decreased symptoms compared to Group A and C. Glutathione level dropped significantly in the control group (p < 0.05) and increased (p > 0.05) in groups B and C mice who received TQ injections. We also noted that EAE clinical signs correlated well with the extent of perivascular lymphocyte infiltrate compared with normal histology following TQ injections. Our results indicate that TQ, due to its anti-oxidant effects is almost 80% preventive and 50% curative in CR-EAE. These results could assist further studies on the mechanism of the action of TQ in CR-EAE and on the possibility of treating the chronic- relapsing phase of human multiple sclerosis. It seems within the realm of possibility that TQ may be as, if not more, therapeutically efficacious as interferon â and glatiramer acetate.
4

Mapeamento de caracteres do tegumento da semente de soja e análise in silico dos marcadores microssatélites / Genetic mapping of soybean seed and in silico analysis of the microssatelites markers

Henning, Fernando Augusto 30 April 2007 (has links)
Made available in DSpace on 2014-08-20T13:44:42Z (GMT). No. of bitstreams: 1 dissertacao_fernando_henning.pdf: 464142 bytes, checksum: dafd04da655722e31d27a17fb98fb36d (MD5) Previous issue date: 2007-04-30 / The use of quality seeds is preponderant to obtain productive success in farming. Several are the factors that influence in the quality of seeds, and among these the flotations can be mentioned in the humidity of seeds and even the use of inadequate techniques in the crop. The coat of soybean seeds is the responsible for the protection of the embryo, therefore, more resistance to you factor that they will take the quality loss, minor will be the damages for the whole productive chain of soybean seeds. The introduction of characters of larger resistance of coat of soybean seed is related to the characteristic of the permeability of coat. Several studies demonstrate to exists soybean genotypes with different permeability characteristics. Based on these information took place the crossing among to cultivate commercial CD202 (yellow and permeable coat) with a lineage TP (black and semi-permeable coat). In the population generated by the crossing, grew this work with the following objectives: i) to Build a genetic map of the coat of soybean seed using markers microssatélites, RAPD and AFLP; ii) to Relate the markers microssatélites used in the construction of the genetic map of the coat of soybean, with the possible proteins codified by the sequences anchored by these markers in the bank of ESTs of the soybean. For the construction of the genetic map of the coat of soybean 600 primers microssatélites, 50 RAPD and 64 AFLP were tested. The markers selected as polimórficos, they were submitted to the analysis of Qui-square and contained in connection groups using the program MapMaker. The alignment among the sequences of the microssatélites with the database of ESTs was made through analyses in silico being used the program BLAST. Of the total of tested markers, they were used in the construction of the map 20 markers microssatélites, 2 RAPD and 11 AFLP, which were efficient in the formation of 13 connection groups. Among the 20 markers selected microssatélites, 4 presented homology with sequences of ESTs deposited in the database of the soybean, and some of these sequences possess indirect relationship with the quality of soybean seeds. / A utilização de sementes de qualidade é preponderante para se obter sucesso produtivo em uma lavoura. Diversos são os fatores que influenciam na qualidade das sementes, sendo que dentre estes podem-se citar as flutuações na umidade das sementes e até mesmo a utilização de técnicas inadequadas na colheita. O tegumento das sementes de soja é o responsável pela proteção do embrião, logo, quanto maior sua resistência a fatores que irão levar a perda de qualidade, menores serão os prejuízos para toda a cadeia produtiva de sementes de soja. A introdução de caracteres de maior resistência do tegumento da semente de soja está relacionada à característica da permeabilidade do tegumento. Diversos estudos demonstram existir genótipos de soja com diferentes características de permeabilidade. Baseado nestas informações realizou-se o cruzamento entre a cultivar comercial CD202 (tegumento amarelo e permeável) com uma linhagem TP (tegumento preto e semi-permeável). Na população gerada pelo cruzamento, desenvolveu-se este trabalho com os seguintes objetivos: i) Construir um mapa genético do tegumento da semente de soja utilizando marcadores microssatélites, RAPD e AFLP; ii) Relacionar os marcadores microssatélites utilizados na construção do mapa genético do tegumento da soja, com as possíveis proteínas codificados pelas seqüências ancoradas por estes marcadores no banco de ESTs da soja. Para a construção do mapa genético do tegumento da soja foram testados 600 primers microssatélites, 50 RAPD e 64 AFLP. Os marcadores selecionados como polimórficos, foram submetidos à análise de Qui-quadrado e agrupados em grupos de ligação utilizando o programa MapMaker. O alinhamento entre as seqüências dos microssatélites com o banco de dados de ESTs foi feito via análises in silico utilizando-se o programa BLAST. Do total de marcadores testados, foram utilizados na construção do mapa 20 marcadores microssatélites, 2 RAPD e 11 AFLP, os quais foram eficientes na formação de 13 grupos de ligação. Dentre os 20 marcadores microssatélites selecionados, 4 apresentaram homologia com seqüências de ESTs depositadas no banco de dados da soja, sendo que algumas destas seqüências possuem relação indireta com a qualidade de sementes de soja.

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