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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

The antimicrobial activity and Phytochemistry of leaf essential oils of selected rutaceae species

Khusal, Pristish 07 1900 (has links)
A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg. in partial fulfilment of the requirements for the degree of Master of Science in Medicine ( Pharmaceutical Affairs ) / The Retuceae is an aromatic family of plants confined to the Fynbos biome in South Africa. This family is represented by a number of genera e.g. Agasthosma, Adenandra, Coleonema, Vepris etc. all containing a number of species which have been used for centuries in traditional healing. Although many of these species have been used for centuries in local healing rites the biological activity and phytochemistry are poorly recorded. / IT2018
2

The composition and antimicrobial activity of leaf essential oils of selected agathosma species ( rutaceae )

Fourie, Carla 14 November 2003 (has links)
A research report submitted to the faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Medicine ( Pharmaceutical Affairs ) / This project was conducted to investigate properties and to record the essential oil profiles of a selection of species belonging to the genus agasthosma. Plants have been used for many years by the local South African to treat various infections and illnesses. This knowledge has largely been untapped. Buchu is one of the plant species that are used extensively by the San and Khoi people. It is remarkable that of the ca. 150 agathosma species indigenous to South Africa only two species ( Agasthosma crenulata and agathosma betulina ) have been investigated for biological activity. The genus Agasthosma is traditionally used for the following conditions ; stomach ailments, fever, coughs, cold, flu, urinary tract, and kidney infections, haematuria, prostatitis, rheumatism, gout, bruises and for antiseptic purposes. / IT2018
3

The composition, geographical variation and antimicrobial activity of Lippia javanica ( Verbenaceae ) leaf essential oils

Subramoney, Sivanasen January 2003 (has links)
A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master in Science ( Medicine ) Pharmaceutical Affairs / Lippia javanica is a widely spread woody shrub and the major traditional use is reflected in its vernacular name; fever tea ' koorsbossie '. An infusion of the leaves is also used as a decongestant for colds and coughs. Infusions may also be used topically to treat scabies and lice A preliminary study indicated that the essential oil chemistry varies dramatically both within and between natural plant populations. / IT2018
4

Allelopathic potential of the alien invader weed Campuloclinium macrocephalum (Less)D.C.

Dixon, Gemma Michelle 05 October 2009 (has links)
It has been suggested that the Category 1 weed, Campuloclinium macrocephalum (Less) D.C has allelopathic potential, which would, at least partially, explain its apparent success as an alien plant in South Africa. Studies were done on the plant’s root, stems and leaves to determine where the strongest allelopathic potential can be found. Once it was determined that the leaves held the strongest potential, bioassay studies were conducted on lettuce (Lactuca sativa), Eragrostis tef, Eragrostis curvula and Panicum maximum with positive results found for C. macrocephalum’s allelopathic potential. Electron microscopy was performed to determine whether allelopathic substances originate and/or are stored on the surfaces of the leaf. Positive results proved that there are possible sources of allelochemicals on both adaxial and abaxial surfaces of young and mature leaves. A dipping experiment involving dichloromethane then followed to determine the solubility of the contents of the glands found on the leaf surfaces. It can be deduced from results of all of the experiments performed that C. macrocephalum is potentially allelopathic to dicotyledonous species and to grasses. Structures found on the leaves of the plant could possibly contain the allelochemicals used by the plant to ensure its successful invasive growth habits in South Africa. The allelopathic effects that this weed will have on desirable species should be considered within the broader context of its ability to interfere with those species. In this regard its competitive ability should also be studied. Campuloclinium macrocephalum is fast invading susceptible areas of South Africa; if continuous research on control and eradication of this plant is not carried out soon, the country could suffer grave economic losses. Copyright / Dissertation (MInstAgrar)--University of Pretoria, 2009. / Plant Production and Soil Science / unrestricted
5

Development of latent prints on fruits, vegetables, and plant leaves using fingerprint powder, magnetic powder, and Lumicyano superglue fuming

Hiroi, Reika 18 November 2021 (has links)
Latent prints can be used as evidence in crime scenes to connect individuals to the location of a potential crime. In some cases, perpetrators may handle partially eaten fruits at the scene of a crime and leave latent fingerprints on the surface of the fruit. Plant leaves of common household ornamental plants and regional shrubs may also be a potential source of latent prints. Fruits, vegetables, and plant leaves have not been extensively studied as substrates for fingerprint development. In order to assess the feasibility of developing and visualizing latent prints on fruits, vegetable, and plant leaf surfaces, black and white fingerprint powder, bi-chromatic magnetic powder, and LumicyanoTM superglue fuming were utilized on tomato, zucchini, cucumber, acorn squash, carrot, mango, plum, pear, orange, pepper, banana, watermelon, Rhododendron leaf, Philodendron leaf, and Jasmine leaf. An aging study up to sixteen days was also conducted on eight of the fifteen substrates to determine the effects of aging on latent fingerprint impression development. Latent prints were recovered from all surfaces with the three techniques. Using a scoring system of 0-2, in which 2 represents the presence of six or more minutiae and 0 represents the lack of minutiae, impressions developed with fingerprint powder scored the highest average across all substrates. The aging study revealed a general decline in the quality of the latent prints over time with LumicyanoTM fuming performing the best.
6

Hypolipidemic, antioxidative and vascular effects of soy leaves (Glycine max L. Merr.).

January 2001 (has links)
Ho Hing Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 140-156). / Abstracts in English and Chinese. / Chapter Chapter 1 --- General introduction / Chapter 1.1 --- History of soybean --- p.1 / Chapter 1.2 --- Health benefits of soybean --- p.2 / Chapter 1.3 --- Introduction to flavonoids --- p.2 / Chapter 1.4 --- Bioavailability of flavonoids from foods --- p.3 / Chapter 1.5 --- Pharmacological effects of flavonoids and their glycosides --- p.4 / Chapter 1.5.1 --- Anticarcinogenic activity --- p.4 / Chapter 1.5.2 --- Antioxidative activity --- p.7 / Chapter 1.5.3 --- Cardioprotective activity --- p.9 / Chapter 1.5.4 --- Osteoprotective activity --- p.10 / Chapter 1.5.5 --- Neuroprotective activity --- p.12 / Chapter 1.5.6 --- Antiangiogenic activity --- p.12 / Chapter 1.6 --- Soy leaves --- p.13 / Chapter Chapter 2 --- Isolation and purification of kaempferol glycosides and genistin in soy leaves / Chapter 2.1 --- Introduction --- p.14 / Chapter 2.2 --- Objectives --- p.15 / Chapter 2.3 --- Materials and Methods --- p.16 / Chapter 2.3.1 --- Extraction and isolation --- p.16 / Chapter 2.3.1.1 --- Preparation of soy leaves butanol extract --- p.16 / Chapter 2.3.1.2 --- Preparation of kaempferol glycosides from soy leaves butanol extract --- p.16 / Chapter 2.3.2 --- High performance liquid chromatography (HPLC) analysis --- p.19 / Chapter 2.3.2.1 --- Sample preparation for the HPLC analysis --- p.19 / Chapter 2.3.2.2 --- HPLC analysis --- p.19 / Chapter 2.3.2.3 --- Quantification of the flavonoids and their glycosides --- p.23 / Chapter 2.3.2.4 --- Change in flavonoids and their glycosides in soy leaves --- p.23 / Chapter 2.4 --- Results --- p.24 / Chapter 2.4.1 --- Compound 1 --- p.24 / Chapter 2.4.2 --- Compound 2 --- p.24 / Chapter 2.4.3 --- Compound 3 --- p.25 / Chapter 2.4.4 --- Compound 4 --- p.25 / Chapter 2.4.5 --- Compound 5 --- p.25 / Chapter 2.4.6 --- Compound 6 --- p.26 / Chapter 2.4.7 --- Quantification of flavonoids in soybean and soy leaves --- p.32 / Chapter 2.4.8 --- Age-dependent changes in flavonoids and their glycosides --- p.32 / Chapter 2.5 --- Discussion --- p.35 / Chapter 2.5.1 --- Compound 1 --- p.35 / Chapter 2.5.2 --- Compound 2 --- p.35 / Chapter 2.5.3 --- Compound 3 --- p.37 / Chapter 2.5.4 --- Compound 4 --- p.38 / Chapter 2.5.5 --- Compound 5 --- p.39 / Chapter 2.5.6 --- Compound 6 --- p.40 / Chapter 2.5.7 --- Age-dependent changes in flavonoids and their glycosides --- p.40 / Chapter Chapter 3 --- Hypolipidemic effects of soy leaves in hamsters / Chapter 3.1 --- Introduction --- p.41 / Chapter 3.1.1 --- Different lipoproteins and their functions --- p.41 / Chapter 3.1.2 --- Risk factors of cardiovascular disease --- p.42 / Chapter 3.1.3 --- Animal model --- p.43 / Chapter 3.2 --- Objectives --- p.44 / Chapter 3.3 --- Materials and Methods --- p.45 / Chapter 3.3.1 --- Animals --- p.46 / Chapter 3.3.2 --- Serum lipid and lipoprotein determinations --- p.46 / Chapter 3.3.3 --- Determination of cholesterol in the liver and adipose tissue --- p.46 / Chapter 3.3.4 --- Extraction of neutral and acidic sterols from fecal samples --- p.49 / Chapter 3.3.4.1 --- Determination of neutral sterols --- p.49 / Chapter 3.3.4.2 --- Determination of acidic sterols --- p.50 / Chapter 3.3.4.3 --- GLC analysis of neutral and acidic sterols --- p.51 / Chapter 3.3.5 --- Statistics --- p.51 / Chapter 3.4 --- Results --- p.54 / Chapter 3.4.1 --- Growth and food intake --- p.54 / Chapter 3.4.2 --- "Effects of SLP and SLEE supplementation on serum triacylglycerol (TG), total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C)" --- p.54 / Chapter 3.4.3 --- Effects ofSLP and SLEE supplementation on non-HDL-C and ratio of non-HDL-C to HDL-C --- p.55 / Chapter 3.4.4 --- Effects of SLP amd SLEE supplementations on concentration of hepatic cholesterol --- p.58 / Chapter 3.4.5 --- Effects of SLP and SLEE supplementations on perirenal adipose tissue cholesterol --- p.58 / Chapter 3.4.6 --- Effects of SLP and SLEE supplementations on fecal neutral and acidic sterols --- p.61 / Chapter 3.5 --- Discussion --- p.64 / Chapter Chapter 4 --- Effects of soy leaves and its flavonoid glycosides on haemolysis and on LDL oxidation / Chapter 4.1 --- Introduction --- p.67 / Chapter 4.1.1 --- Role of low density lipoprotein oxidation in the development of atherosclerosis --- p.68 / Chapter 4.1.2 --- LDL oxidation --- p.70 / Chapter 4.1.3 --- Thiobarbituric acid reactive substances (TBARS) as an index of LDL oxidation --- p.71 / Chapter 4.1.4 --- Antioxidant and LDL oxidation --- p.74 / Chapter 4.2 --- Objective --- p.75 / Chapter 4.3 --- Materials and methods --- p.76 / Chapter 4.3.1 --- Isolation of LDL from human serum --- p.76 / Chapter 4.3.2 --- LDL oxidation --- p.77 / Chapter 4.3.3 --- Determine the formation of thiobarbituric acid-reactive substances (TBARS) --- p.77 / Chapter 4.3.4 --- Assay for erythrocyte haemolysis --- p.78 / Chapter 4.3.5 --- Statistics --- p.79 / Chapter 4.4 --- Results --- p.80 / Chapter 4.4.1 --- Effects of three different soy leaves extracts and flavonoid glycosides on LDL oxidation --- p.80 / Chapter 4.4.2 --- Effects of three soy leaves extracts and flavonoid glycosides on erythrocyte haemolysis --- p.80 / Chapter 4.5 --- Discussion --- p.85 / Chapter Chapter 5 --- Relaxing effects of soy leaves and its flavonoids / Chapter 5.1 --- Introduction --- p.89 / Chapter 5.1.1 --- Smooth muscle contraction --- p.90 / Chapter 5.1.1.1 --- Sliding filament mechanism --- p.91 / Chapter 5.1.2 --- Intracellular mechanisms involved in the regulation of smooth muscle contraction --- p.92 / Chapter 5.1.2.1 --- Voltage-gated Ca2+ channels --- p.92 / Chapter 5.1.2.2 --- Protein kinase C (PKC) mediated smooth muscle contraction --- p.93 / Chapter 5.1.2.3 --- Thromboxane A2 receptor-mediated calcium channel --- p.94 / Chapter 5.2 --- Objectives --- p.96 / Chapter 5.3 --- Materials and methods --- p.97 / Chapter 5.3.1 --- Drugs preparation --- p.97 / Chapter 5.3.2 --- Vessel preparation --- p.97 / Chapter 5.3.3 --- Contraction experiments --- p.99 / Chapter 5.3.3.1 --- Relaxant responses of soy leaves butanol extract on the contraction induced by different constrictors --- p.99 / Chapter 5.3.3.2 --- Relaxant responses of soy leaves butanol extract on U46619 and PGF2a- induced contraction --- p.99 / Chapter 5.3.3.3 --- "Relaxant responses of genistein, genistin and the kaempferol glycosides on U46619-induced contraction" --- p.100 / Chapter 5.3.4 --- Statistics --- p.100 / Chapter 5.4 --- Results --- p.102 / Chapter 5.4.1 --- Effect of soy leaves butanol extract --- p.102 / Chapter 5.4.2 --- Role of endothelium in extract-induced relaxation --- p.102 / Chapter 5.4.3 --- Effect of the soy leaves butanol extract on contractile response to prostaglandins --- p.103 / Chapter 5.4.4 --- Effects of kaempferol glycosides and kaempferol --- p.111 / Chapter 5.4.5 --- Effects of genistein and genistin --- p.111 / Chapter 5.5 --- Discussion --- p.118 / Chapter Chapter 6 --- Effect of soy leaves on mammary tumor / Chapter 6.1 --- Introduction --- p.123 / Chapter 6.1.1 --- Carcinogenesis --- p.123 / Chapter 6.1.1.1 --- In itiation --- p.124 / Chapter 6.1.1.2 --- Promotion --- p.124 / Chapter 6.1.1.3 --- Progression --- p.125 / Chapter 6.2 --- Objective --- p.126 / Chapter 6.3 --- Materials and methods --- p.127 / Chapter 6.3.1 --- Animal --- p.127 / Chapter 6.3.2 --- Determination of estrus cycle --- p.128 / Chapter 6.3.3 --- Statistics --- p.129 / Chapter 6.4 --- Results --- p.131 / Chapter 6.4.1 --- Incident rate of tumor induction --- p.131 / Chapter 6.4.2 --- Number of tumor induced --- p.131 / Chapter 6.5 --- Discussion --- p.136 / Chapter Chapter 7 --- Conclusions --- p.136 / References --- p.140
7

Acoustic properties of low growing plants

Horoshenkov, Kirill V., Khan, Amir, Benkreira, Hadj January 2013 (has links)
No / The plane wave normal incidence acoustic absorption coefficient of five types of low growing plants is measured in the presence and absence of soil. These plants are generally used in green living walls and flower beds. Two types of soil are considered in this work: a light-density, man-made soil and a heavy-density natural clay base soil. The absorption coefficient data are obtained in the frequency range of 50-1600 Hz using a standard impedance tube of diameter 100 mm. The equivalent fluid model for sound propagation in rigid frame porous media proposed by Miki [J. Acoust. Soc. Jpn. (E) 11, 25-28 (1990)] is used to predict the experimentally observed behavior of the absorption coefficient spectra of soils, plants, and their combinations. Optimization analysis is employed to deduce the effective flow resistivity and tortuosity of plants which are assumed to behave acoustically as an equivalent fluid in a rigid frame porous medium. It is shown that the leaf area density and dominant angle of leaf orientation are two key morphological characteristics which can be used to predict accurately the effective flow resistivity and tortuosity of plants.
8

Sound absorption of porous substrates covered by foliage: experimental results and numerical predictions

Ding, L., Van Renterghem, T., Botteldooren, D., Horoshenkov, Kirill V., Khan, Amir January 2013 (has links)
No / The influence of loose plant leaves on the acoustic absorption of a porous substrate is experimentally and numerically studied. Such systems are typical in vegetative walls, where the substrate has strong acoustical absorbing properties. Both experiments in an impedance tube and theoretical predictions show that when a leaf is placed in front of such a porous substrate, its absorption characteristics markedly change (for normal incident sound). Typically, there is an unaffected change in the low frequency absorption coefficient (below 250 Hz), an increase in the middle frequency absorption coefficient (500-2000 Hz) and a decrease in the absorption at higher frequencies. The influence of leaves becomes most pronounced when the substrate has a low mass density. A combination of the Biot's elastic frame porous model, viscous damping in the leaf boundary layers and plate vibration theory is implemented via a finite-difference time-domain model, which is able to predict accurately the absorption spectrum of a leaf above a porous substrate system. The change in the absorption spectrum caused by the leaf vibration can be modeled reasonably well assuming the leaf and porous substrate properties are uniform.
9

AFM relative stiffness measurement of the plasticising effect of a non-ionic surfactant on plant leaf wax

Grant, Colin A., Twigg, Peter C., Bell, G., Lu, J.R. January 2008 (has links)
An AFM relative stiffness technique was applied to reconstituted Beta vulgaris L. wax films. Consecutive force arrays (n=100) made on the waxy surface at the same locations showed that there was no relative change in surface elasticity and this information was used as a reference to further experimental measurements. A surfactant solution was subsequently dropped on the waxy surface and the same array of indents was made at the same location as the reference test. The plant wax surface showed a reduction in its surface elasticity properties. The study has demonstrated that the AFM technique could be used to undertake a systematic assessment of the plasticising effects of agrochemicals on native and reconstituted plant wax films.
10

Quantitative and qualitative investigation of adhesion and friction on textured surfaces : inspiration from insect-plant interactions / Étude qualitative et quantitative de l'adhésion et du frottement sur surfaces texturées : inspiration des interactions entre insectes et plantes

Kumar, Charchit 28 May 2019 (has links)
L’adhérence et le frottement existent dans de nombreux systèmes techniques ainsi que dans les systèmes naturels. Ces deux phénomènes ont une influence importante sur la durabilité et l’efficacité des dispositifs techniques. Une approche reconnue pour ajuster précisément ces caractéristiques - outre le fait de modifier les propriétés physico-chimiques - est la texturation des surfaces en contact. Les surfaces de feuilles de plantes sont souvent décorées avec des morphologies de surface diverses, et présentent ainsi des fonctionnalités de surface remarquables. Cette thèse visait à réaliser une étude systématique de la mécanique de l’adhérence et du frottement sur des surfaces micro-structurées, répliquées à partir de surfaces de feuilles végétales, en contact avec une sonde qui s’inspire de l’organe adhérent d’un insecte. Les morphologies de surface de trois feuilles végétales différentes ont été directement transférées sur un polymère viscoélastique. Pour ce faire, trois approches différentes de reproduction ont fait l’objet d’une étude approfondie. La microscopie électronique à balayage et la microscopie confocale à balayage laser ont été utilisées pour l'évaluation qualitative et quantitative de la qualité de reproduction. Concernant l’étude de la mécanique du contact, un nano-indenteur a été modifié, permettant d’enregistrer les images in situ des contacts réels. Des tests de pull-off ont été menés afin d’évaluer quantitativement l’effet de la pré-charge sur la force d’adhésion et pour comprendre les modes distincts de collage/décollement. Des essais de frottement ont été effectués afin d’examiner l’effet de la charge normale et de la vitesse de glissement sur la force de frottement. Les résultats ont été discutés en fonction de la topographie de chaque surface. / Adhesion and friction exist in many technical systems as well as in natural ones. Both phenomena have a profound influence on the durability and efficiency of technical systems. A well-recognised way to tune these characteristics - besides altering the physicochemical properties - is the texturing of the interacting surfaces. Inspiringly, plant leaf surfaces are often decorated with diverse surface morphologies, and so show remarkable functionalities. This thesis aimed to perform a systematic investigation of adhesion and friction mechanics on micro-structured surfaces replicated from plant leaves, in contact with a probe, which was inspired from an insect’s adhesive pad. Surface morphologies of three different plant leaves were directly transferred onto a viscoelastic polymer. For this, three different replication approaches were comprehensively explored. Scanning electron microscopy and confocal laser scanning microscopy were used for the qualitative and quantitative evaluation of replication ability. For the contact mechanics investigation, a high-resolution nanoindenter was modified, with incorporating a unique feature to record the in-situ real-contact images. Pull-off tests were carried out to quantitatively evaluate the effect of pre-load on adhesion force characteristics and to understand distinct attachment-detachment modes. Friction investigations were performed to examine the effect of normal load and sliding speed on the friction force. Results were discussed with regard to each surface’s topography.

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