• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 593
  • 339
  • 56
  • 53
  • 32
  • 27
  • 19
  • 19
  • 19
  • 19
  • 19
  • 19
  • 10
  • 9
  • 9
  • Tagged with
  • 1350
  • 220
  • 209
  • 147
  • 133
  • 115
  • 111
  • 102
  • 100
  • 95
  • 81
  • 80
  • 69
  • 62
  • 59
  • 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.
321

Perfil epidemiologico dos casos de acidentes ofidicos atendidos no hospital de doencas tropicais de Araguaia - To (trienio 2007-2009) / Epidemiological profile cases of snakebites treated at the hospital for tropical diseases in Araguaina - TO (years 2007-2009)

PAULA, RUTH C.M.F. de 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:27:49Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:55Z (GMT). No. of bitstreams: 0 / Os acidentes causados por serpentes peçonhentas são considerados um problema de saúde pública no Brasil, e é muito importante que sejam feitos mais estudos para um melhor conhecimento desse agravo. O objetivo deste trabalho é descrever as características clínicas e epidemiológicas que foram observados no Hospital de Doenças Tropicais de Araguaína, Estado do Tocantins, Brasil, que é uma unidade de saúde que cuida de pacientes que sofrem de doenças tropicais, no período de 2007 a 2009. Foram estudados 556 indivíduos e as características mais comuns observadas foram: sexo masculino, idade entre 19-40 anos, picada em membros inferiores e os ferimentos causados por serpentes do gênero Bothrops. Os sinais e sintomas mais freqüentes foram dor, edema e hemorragia. A manifestação sistêmica mais observada foi alteração da coagulação sanguínea. As complicações mais freqüentes foram abscesso, insuficiência renal aguda, necrose e infecção bacteriana. Os principais microorganismos identificados foram Morganela morganii (17,1%), Pseudomonas aeruginosa (14,6%) e Staphylococcus epidermidis (4,9%). Esta flora bacteriana foi semelhante às descritas no veneno e na boca das serpentes por outros pesquisadores. Com base nos resultados dos testes de suscetibilidade sugere-se a continuidade no uso de ciprofloxacin para o tratamento desses abscessos que não respondem à simples drenagem. O conjunto dos resultados obtidos representa um completo levantamento da atual situação dos acidentes envolvendo serpentes no estado do Tocantins e arredores e certamente contribuirá para o aprimoramento das ações de combate aos problemas de Saúde Pública da região Norte. / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
322

Estudo da redução microbiana intracanal utilizando laser de baixa potência associado a fotossensibilizador e laser de alta potência

KAIRALLA, ELENI C. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:54:51Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:57Z (GMT). No. of bitstreams: 1 12794.pdf: 2065231 bytes, checksum: 5d277cd94726f9af455400aea420ffe2 (MD5) / Dissertacao (Mestrado Profissionalizante em Lasers em Odontologia) / IPEN/D-MPLO / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP; Faculdade de Odontologia, Universidade de Sao Paulo, Sao Paulo
323

Die aktiwiteit van mikroorganismes in die ground van die Savanne-Ekosisteem by Nylsvley

Bezuidenhout, Johannes Jurgens January 1978 (has links)
Please read the abstract in the dissertation. / Dissertarion (MSc)--University of Pretoria, 1978 / gm2013 / Mathematics and Applied Mathematics / unrestricted
324

Phylogenetic diversity of nifH genes in Marion Island soil

Rapley, Joanne January 2006 (has links)
Magister Scientiae - MSc / The microbial life of sub-Antarctic islands plays a key role in the islands ecosystem, with microbial activities providing the majority of nutrients available for primary production. Knowledge of microbial diversity is still in its infancy and this is particularly true regarding the diversity of micro-organisms in the Antarctic and sub-Antarctic regions. One particularly important functional group of micro-organisms is the diazotrophs, or nitrogen-fixing bacteria and archaea. This group have not been well studied in the sub-Antarctic region, but play an important role in the nutrient cycling of the island. This thesis explored the diversity of nitrogen-fixing organisms in the soil of different ecological habitats on the sub-Antarctic Marion Island. / South Africa
325

Matrix comparison of isolation conditions for secondary metabolite producing marine sponge associated bacteria

Matobole, Relebohile Matthew January 2015 (has links)
>Magister Scientiae - MSc / The discovery of novel secondary metabolites has declined significantly in recent years whereas there is a rise in the number of multi-drug resistant pathogens and other types of diseases. The decline in natural product discovery was due to high rediscovery of already known compounds and the costs in developing natural products. As a result pharmaceutical companies lost interest in investing in natural product discovery. However, there is a renewed interest in marine sponge associated microorganisms as a rich and untapped source of secondary metabolites. The objective of this study was to design a matrix to investigate the extent to which the One Strain-Many Compounds (OSMAC) approach applies to a collection of marine sponge isolates harvested from two South African marine sponge samples. Terminal restriction fragment length polymorphisms (T-RFLP) analysis was used to investigate and ascertain the two marine sponges which hosted the highest microbial diversities to be used for further culture-dependent studies. The culture-dependent studies, using 33 media which included liquid enrichment, heat treatments and antibiotic treatments, resulted in 400 sponge isolates from the two marine sponges Isodictya compressa and Higginsia bidentifera. Using antibacterial overlay assays, 31 dereplicated isolates showed antibacterial activity. Bioactivities were also exhibited against E. coli 1699 which is genetically engineered for resistance against 52 antibiotics which implies that some of the bioactive compounds could be novel. The 16S rRNA gene sequences revealed that the microbial phyla isolated from the marine sponges belonged to Actinobacteria, Firmicutes and Proteobacteria (Alphaproteobacteria and Gammaproteobacteria).Thirty isolates were selected for an OSMAC-based matrix study, 17 of which showed noantibacterial activities in preliminary screening. The application of the OSMAC approach using co-culture and 36 culture conditions resulted in 6 isolates showing antibacterial activities, three of which did not show activities in preliminary screening. One of these, a Bacillus pumilus isolated from I. compressa displayed antibacterial activity against 5 indicator strains whereas in preliminary screening it had not shown activity. The results show that marine sponges can host novel microbial species which may produce novel bioactive compounds. The results also confirm that traditional methods employing a single culture condition restricts the expression of some biosynthetic pathways of microorganisms and as a result many metabolites have yet to be identified.
326

Sulphur metabolism in microorganisms

Jones-Mortimer, M. C. January 1967 (has links)
No description available.
327

The metabolic function of p-hydroxybenzoic acid and related compounds in micro-organisms

Wyn Jones, R. G. January 1966 (has links)
No description available.
328

Development of PCR-based detection assays for Legionella pneumophila in water

Goosen, Coenie 07 November 2005 (has links)
Please read the abstract on p 79-80 of this document / Dissertation (MSc Agric (Microbiology))--University of Pretoria, 2005. / Microbiology and Plant Pathology / unrestricted
329

Performance of Clostridium perfringens-challenged broilers inoculated with effective microorganisms

Botlhoko, Tuelo David 19 February 2010 (has links)
The first study was conducted to evaluate the dietary inclusion of effective microorganisms (EM) on body weight (BW), feed intake, feed conversion ratio (FCR) and mortality of broilers, which had been either challenged or non-challenged with Clostridium perfringens (1mL of 1 x 108 CFU/mL orally). Six hundred and forty day-old Ross 788 broiler chicks were randomly allocated to thirty-two pens in groups of twenty birds per pen, giving a stocking density of ±18 birds per square meter from zero to forty days of age. The facility consisted of two rooms with sixteen pens per room. All the chicks were fed on a commercial maize-soya type diet, including a mash starter and a mash grower/finisher feed. At two weeks of age 320 chicks were inoculated with Clostridium perfringens type A through oral administration. The study had a randomised block design with four replicates and four treatments as: 1) Control-unmedicated; 2) antibiotic growth promoters (AGP) added to feed at 33g/kg; 3) EM added to feed and water at 50g/kg and 50mL/L respectively; and 4) AGP in feed at 33g/kg and EM (50g/kg) in feed and water (50mL/L). The inclusion of EM negatively affected water palatability that resulted in reduced water intake and increased FCR for the non-challenged broilers at 21 days of age. However, because feed intake was not affected, it was suggested that EM should rather be supplemented through the feed rather than through the water. The use of AGP alone or in combination with EM proved (P<0.05) broiler production performance. The cumulative feed intake, BW, FCR, average daily gain (ADG), cumulative water intake and production efficiency factor (PEF) of challenged broilers were not different (P>0.05) at 40 days of age. In this study the incidence of mortality was low (2.2%) and examination of livers and intestines showed only mild necrotic enteritis lesions. In conclusion, the findings of this study showed that EM under the current dosage failed to improve broiler production performance. A second experiment was conducted as a follow-up study to evaluate the effect of EM on broiler performance when supplemented through the feed only. Cloacal swabs were taken from all day-old chicks and a day after inoculation with Clostridium perfringens for laboratory analysis of the microorganisms in the gut. All the chicks were fed on a commercial two-phase maize-soya type diet consisting of a mash starter and a mash grower/finisher feed with additional fishmeal. The chicks from one room were inoculated orally with Clostridium perfringens, while the chicks from the other room remained unchallenged. The challenged group was inoculated orally with 1 mL (1 x 108 CFU/mL) of Clostridium perfringens as a single dose on day 14. The EM was supplemented to the broilers from day one through the feed. The supplementation of EM through the feed showed a poor performance for non-challenged whilst for the challenged showed an improved performance at 3 weeks. Both non-challenged and challenged broilers given EM had a poor performance at 6 weeks of age, and this showed inconsistent results throughout the experiment. However, it was found that the combination of both AGP and EM had a better performance than EM alone. It is noted when the results of broilers nonchallenged versus challenged control groups were compared, the challenged ones showed a better performance. The broilers showed a low mortality of 1.3% and the causes were not related to the incidence of necrotic enteritis. The gross examination of the broilers inoculated orally with Clostridium perfringens showed mild intestinal lesions. Copyright / Dissertation (MSc(Agric))--University of Pretoria, 2010. / Animal and Wildlife Sciences / unrestricted
330

The potential of spice oils in the control of mycotoxin producing fungi

Juglal, Sarla January 2000 (has links)
Submitted in fulfillment of the requirements for the Degree of Master of Technology: Biological Sciences at Technikon Natal, 2000. / Spice oils are known to exhibit antifungal activity and therefore have the potential to control mycotoxin production. There is a need in the food industry to find measures to control mycotoxins that are frequently associated with grains that form the staple diet of the majority of the population in South Africa. Clove, cinnamon, oregano, tumeric, eucalyptus, neem, aniseed, mace and nutmeg oils were tested to determine their inhibitory potential against growth of Aspergillus parasiticus and Fusarium moniliforme using the agar overlay technique. Varying concentrations of the spice oils, ranging from 0.1 ppm to 2.0 ppm, were incorporated into broth cultures of A. parasiticus and maize patty cultures ofF. moniliforme. Levels of production of aflatoxins and fumonisin were determined using standard thin layer chromatography and highpressure liquid chromatography methods. In addition, the active component of the spice oils were isolated, characterised and tested. The inhibitory potential of these compounds for field use was tested by incorporating clove oil, whole cloves and ground cloves in samp / M

Page generated in 0.0634 seconds