Interaction of the neurotransmitter acetylcholine with aluminium, calcium and sodium
- Authors: Matlaba, Pulane M , Daya, Santy , Nyokong, Tebello
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293246 , vital:57068 , xlink:href="https://doi.org/10.1211/146080800128735890"
- Description: Binding of aluminium to acetylcholine has important biological implications particularly in Alzheimer's disease. An electrochemical technique, adsorptive cathodic stripping voltammetry, has been employed in this study to investigate the in-situ formation of a complex between aluminium and acetylcholine. The stability of the resulting complex was compared with that of the in-situ complexes formed between acetylcholine and sodium or calcium. From the shifts in the reduction potential of the metals on addition of acetylcholine it is concluded that a strong complex is formed between acetylcholine and aluminium. Much weaker complexes are formed between calcium or sodium and acetylcholine. These results have important implications in the aetiology of Alzheimer's disease-in which brain aluminium concentrations are known to be high and brain cholinergic function is lower than normal.
- Full Text:
- Date Issued: 2000
Melatonin alters the photodegradation of paracetamol
- Authors: Anoopkumar-Dukie, Shailendra , Glass, Beverley D , Walker, Roderick B , Daya, Santylal
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184357 , vital:44211 , xlink:href="https://doi.org/10.1211/146080800128735755"
- Description: The effects of melatonin, a known free-radical scavenger, on paracetamol in the presence of UV irradiation was studied by use of HPLC. The experiments were performed in air and nitrogen. The results show that the rate of photodegradation of melatonin is faster in air than in nitrogen whereas that of paracetamol is similar in air and nitrogen. When the two drugs were combined, melatonin retarded the degradation of paracetamol for up to 6h in the presence of nitrogen. However, in the presence of air melatonin rapidly enhances the photodegradation of paracetamol. This study shows that a combination of melatonin and paracetamol in the presence of air and UV irradiation can lead to rapid inactivation of both agents, thus raising important concerns about the possible use of melatonin as sunscreen
- Full Text:
- Date Issued: 2000
Photocatalytic properties of neodymium diphthalocyanine towards the transformation of 4-chlorophenol
- Authors: Nensala, Ngudiankama , Nyokong, Tebello
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/${Handle} , vital:58491 , xlink:href="https://doi.org/10.1016/S1381-1169(00)00283-1"
- Description: Photolysis of aqueous solutions of 4-chlorophenol (4-Cp) in the presence of solid neodymium diphthalocyanine ([Pc(−2)NdPc(−2)]−) and oxygen using visible and ultraviolet (UV) radiation resulted in the formation of a number of products. For photolysis in the visible region, phenol, benzoquinone, hydroquinone were observed as intermediates and 4-chlorocatechol (4-CC) as the main product; intermediates similar to those observed for visible photolysis were obtained. Langmuir–Hinshelwood kinetic model was used for treatment of photochemical data.
- Full Text:
- Date Issued: 2000
Review of policies and legislation influencing the sustainable use of South Africa's indigenous Woodlands
- Authors: Willis, Carla B , Geach, Bev S , Versfeld, Dirk , Shackleton, Charlie M
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182810 , vital:43881 , xlink:href="https://hdl.handle.net/10520/AJA10231765_60"
- Description: The recent completion of the South African National Land-Cover Database and the Vegetation Map of South Africa, Swaziland and Lesotho, allows for the first time a comparison to be made on a national scale between the current and potential distribution of 'natural' vegetation resources. This article compares the distribution and location of woodland-type vegetation categories defined within the National Land-Cover data and the equivalent 'Savanna-thicket Biomes' class defined within the Vegetation Mapdata. Significant differences were found, both in terms of the total areal extent, as well as the actual spatial distribution of these two data sets. These differences are a measure of the inherent mapping accuracies of each source, but rather an illustration of boundary delineation distinctions that are a result of different data sources, mapping objectives and information classes, that must be noted when comparing two essentially similar information sets.
- Full Text:
- Date Issued: 2000
Stump size and the number of coppice shoots for selected savanna tree species
- Authors: Shackleton, Charlie M
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181896 , vital:43778 , xlink:href="https://doi.org/10.1016/S0254-6299(15)31074-7"
- Description: Management of coppice dynamics of indigenous savanna trees could assist in increasing the regrowth rates or number of coppice shoots produced. This would be useful in natural resource management programmes to promote sustainable resource management. This study examined the influence of cutting height, stem size and surface area on the number of coppice shoots produced for twelve savanna species from a communal land in the Bushbuckndge lowveld. All species exhibited a strong coppicing ability following cutting. The number of shoots per stump was most frequently related to cutting height, although this was not always the most significant predictor. There were clear differences between species with respect to the number of shoots per unit surface area, the highest being for Albizia harveyii and the least Piliostlgma thonningii. The taller the potential height of a species, the fewer were the coppice shoots per stump surface area.
- Full Text:
- Date Issued: 2000
The comparative value of wild and domestic plants in home gardens of a South African rural village
- Authors: High, Christopher , Shackleton, Charlie M
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181907 , vital:43779 , xlink:href="https://doi.org/10.1023/A:1006247614579"
- Description: Rural inhabitants make considerable use of wild resources from communal areas around their settlements, as well as from arable and residential plots. These wild resources compete with the main crops planted in arable plots and home gardens, but play a significant economic and nutritional role in rural livelihoods. This paper reports upon a conservative financial evaluation of the wild plant resources harvested from home gardens and arable plots by inhabitants of rural village in the Bushbuckridge lowveld (South Africa), and examines their importance relative to other domesticated crops. On average, each household made use of four to five species of wild plants growing on their residential plot, whereas the mean number of crop plants was 3.4. The total value of all plants was R1694 (US$ 269) per household per year, or approximately R4200 (US$ 667) per hectare of home garden per year. Wild plants represented 31% of the value of all plants grown on residential plots, relative to the 69% for domesticated crops (including fruit trees). Approximately 72% of the total value of all plant products was consumed by the household, and the remaining 28% was sold.
- Full Text:
- Date Issued: 2000
The use of and trade in indigenous edible fruits in the Bushbuckridge savanna region, South Africa
- Authors: Shackleton, Charlie M , Dzerefos, C M , Shackleton, Sheona E , Mathabela, F R
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182396 , vital:43826 , xlink:href="https://doi.org/10.1080/03670244.2000.9991616"
- Description: The use, processing, cultivation and trading of indigenous edible fruits was recorded across a rainfall gradient in the Mpumalanga lowveld. Three transects, each consisting of one village in a relatively high rainfall zone, one village in a low rainfall zone, and one intermediate, were sampled by means of 20 households per village. Nearly all households made use of indigenous edible fruits to some extent, with households in the wettest region using the greatest diversity of fruits. The duration of availability of selected species was increased through drying, storing and processing the raw fruits for later consumption. Such activities were more common in the drier regions relative to the wetter villages. Just less than half the respondents maintained indigenous fruit trees within their homestead or arable fields, whereas more than 65% grew exotic commercial fruit species. Many respondents traded in edible fruits, but very few obtained a significant income in this way. Nonetheless, even casual trading provided vital supplementary income for low‐income households.
- Full Text:
- Date Issued: 2000
Woodlands in South Africa and the national forests act
- Authors: Shackleton, Charlie M
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182065 , vital:43796 , xlink:href="https://doi.org/10.1080/10295925.2000.9631252"
- Description: The development of the National Forestry Action Programme (NFAP) and promulgation of the National Forests Act (NFA) have established a new vision for the care, management and distribution of benefits from South Africa's woodlands. The Department of water Affairs and Forestry is mandated with ensuring this vision is put into practice. However, historically the Department has had little to do with woodlands, and suffers from a lack of capacity and expertise, a situation which it readily acknowledges. Additionally, the legal definition of a woodland within the NFA is problematic. Within this context, this paper examines oft cited definitions of woodlands and seeks to find an appropriate one for the South African context. It then briefly reviews the major classifications of woodland types at a national scale, as the minimum basis for homogenous reporting units for which monitoring of the success of the NFAP and the NFA should be pursued. Finally, a brief description of moist/dystrophic and arid/eutrophic woodlands is presented.
- Full Text:
- Date Issued: 2000
An investigation into the biological treatment of platinum refinery effluent
- Authors: Smith, Roland Paul
- Date: 200u
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/193464 , vital:45334
- Description: This Review and project will discuss and demonstrate the use made of Biotechnology in the production and reduction of metals. It will look at how and why metal binding takes place, known platinum group metal speciation will be included. Examples of how to improve metal binding efficiency will be discussed by stimulating ligand activity by polarisation. Various biotechnical options available, with emphasis placed on the use of the aquatic fern and algae will be given as examples of biological treatment of heavy metals in particular the aquatic fern Azolla. The method of standard preparation and the use of Inductively Coupled Plasma Emission Spectrophotometer (ICP) used for analytical analysis will be included so that consideration can be given to the collection of analytical data in the provision of evidence to support or provide a conclusion. The outcome of the test work utilising the aquatic plant Azolla has proven that it can be used to remediate platinum refinery effluent. This process can offer an alternative to the classical chemical method normally used, which is economically viable and environmentally friendly in comparison to the common methods of refinery effluent treatment. , Thesis (MSc) -- Faculty of Science, Biochemistry, Microbiology and Biotechnology, 200u
- Full Text:
- Date Issued: 200u
Main thesis title: Onderwysers se belewing van multikulturele onderwys
- Authors: Strydom, Louise
- Date: 1999-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: Afrikaans
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/60003 , vital:62732
- Description: The South African Schools’ Act of 1996 terminated segregated education in South Africa. Multi-cultural education has become a reality in the new democratic South Africa. As a result of this major shift in policy, the researcher probed for an answer to the following question: “How does the teacher, especially the teacher already in service, experience this new situation regarding multi-cultural education?” To find an answer to this question, a literature study and empirical research, making use of a representative sample of respondents in the Southern Cape, were undertaken. The researcher has personally experienced the challenges of having to adapt from a mono-cultural teaching environment to a multi-cultural teaching environment at school level, hence a further interest in this research problem. Relevant terminology was highlighted and a brief historical synopsis of the course that multi-cultural education took in Western societies such as the USA, Canada, Australia and Britain was studied. These sources were utilised to draw a comparison with the South African situation. A concise synopsis of the history of multi-cultural education in South Africa was also undertaken to highlight the complexity of the educational situation presently being experienced in South Africa. The empirical research, with a target group representing teachers in the Southern Cape, was undertaken by means of a self-compiled questionnaire to make an analysis of teachers’ attitudes, expectations and perceptions of multi-cultural education as experienced in the classroom. The information obtained from the respondents indicated a generally positive attitude towards multi-cultural education amongst teachers. A great need for in-service training also became evident. xvi The researcher has thus made recommendations regarding in-service training that she thinks is of utmost importance. The practical problems that were highlighted during the research, make a vital contribution towards the successful implementation of multi-cultural education in South Africa. , Thesis (DEd) -- Faculty of Education, 1999
- Full Text:
- Date Issued: 1999-04
Adsorptive cathodic stripping voltammetric determination of gold (III) in the presence of yeast mannan
- Authors: Lack, Barbara , Duncan, John R , Nyokong, Tebello
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293151 , vital:57060 , xlink:href="https://doi.org/10.1016/S0003-2670(98)00736-3"
- Description: Adsorptive cathodic stripping voltammetric (AdCSV) studies of gold(III) on a glassy carbon electrode and in the presence of yeast mannan are reported. These studies give evidence of the formation of a complex between gold(III) and mannan in acid media as judged by the enhancement in the AdCSV currents and shift in the reduction peak of gold(III) in the presence of mannan. The AdCSV currents were linearly dependent on gold(III) concentrations ranging from 7.0 × 10−7 to 3.0 × 10−4 mol dm−3. A detection limit of 6.0 × 10−8 mol dm−3 was obtained. Interferences of copper(II) were observed in the presence of mannan, but there was no significant interference of silver(I).
- Full Text:
- Date Issued: 1999
Cobalt (II) porphyrazine catalysed reduction of nitrite
- Authors: Thamae, Mamothibe , Nyokong, Tebello
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293162 , vital:57061 , xlink:href="https://doi.org/10.1016/S0022-0728(99)00224-7"
- Description: Studies on the catalytic reduction of nitrite on carbon electrodes modified with Co(II) tetra-2,3-pyridinoporphyrazine (CoTppa, 1), N,N′,N′′,N′′′-tetramethyltetra-2,3-pyridinoporphyrazine ([CoTm-2,3-tppa]4+, 2) and Co(II) N,N′,N′′,N′′′-tetramethyltetra-3,4-pyridinoporphyrazine ([CoTm-3,4-tppa]4+, 3) are reported. There is a close correspondence between the proximity of the methyl groups to the porphyrazine ring and the catalytic activity of the porphyrazine complexes. Bulk electrolysis gave ammonia and hydroxylamine as some of the products. The catalytic activity of the cationic complex, 3, towards the detection of low concentrations of nitrite (less than 10−9 M) in water containing sodium sulfate, was compared with the activities of the anionic cobalt(II) tetrasulfophthalocyanine ([CoTSPc]4−, 4) and the mixed [CoIITm-3,4-tppa]4+·[CoTSPc]4− (5) complexes. Complex 5 showed the best catalytic activity of the three in that large currents were obtained for very low concentrations of nitrite.
- Full Text:
- Date Issued: 1999
DSC screening of potential prochlorperazine-excipient interactions in preformulation studies
- Authors: Brown, Michael E , Antunes, Edith M , Glass, Beverley M , Lebete, Mosimotsana L , Walker, Roderick B
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184367 , vital:44212 , xlink:href="https://doi.org/10.1023/A:1010150305542"
- Description: Differential scanning calorimetry was used to examine the thermal behaviour of mixtures of the drug prochlorperazine with standard excipients, to assess potential interactions, and of mixtures with cyclodextrins, to investigate inclusion complexation which could increase the photostability of the drug. For most of the excipients (magnesium stearate, stearic acid, Explotab®, Ac-Di-Sol®, Encompress® and Ludipress®, lactose and Starch 1500) disappearance or broadening of the melting endotherm of the drug indicated interactions. Lubritab® was the only 'inert' excipient tested. Mixtures of prochlorperazine and the cyclodextrins gave incomplete inclusion complexation as shown by only partial disappearance of the melting endotherm of the drug.
- Full Text: false
- Date Issued: 1999
Integrating the development of academic literacy into mainstream teaching and learning
- Authors: Amos, Trevor L
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/270891 , vital:54489 , xlink:href="https://hdl.handle.net/10520/AJA10113487_947"
- Description: Higher education is challenged to develop effective and independent learners of students who experience learning difficulties. These students are however, (potentially) able to engage in and do not necessarily lack the the inherent bstract cognitive capability necessary for academic success. The aim of this article is to be done in practice to integrate the development of academic literacy into mainstream teaching and learning.
- Full Text:
- Date Issued: 1999
Interactions of cobalt (II) tetrasulfophthalocyanine with nitrite in the presence of nitrate and perchlorate ions
- Authors: Chebotareva, Natalia , Nyokong, Tebello
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293257 , vital:57069 , xlink:href="https://doi.org/10.1080/00958979908054907"
- Description: Spectroscopic changes observed on addition of nitrite to solutions of cobalt(II) tetra-sulfophthalocyanine ([Co(II)TSPc]4-) in the presence of N− 3 or ClO− 4 are reported. There is spectroscopic evidence for the oxidation of [Co(II)TSPc]4- to a [Co(III)TSPc]3- species in the presence of nitrite ions. Equilibrium and kinetic studies for the interaction between [Co(II)TSPc]4- and NO− 2 are reported. The rate was found to be first order in both [Co(II)TSPc]4- and NO− 2. The rate constant for the forward reaction, k f=1.6 × 10−4 dm3mol−1s−1 was determined at 20°C for the interaction between nitrite ions and [Co(II)TSPc]4- in the presence of NO3 − or ClO4 − ions.
- Full Text:
- Date Issued: 1999
Towards a semiotic approach to dramatic texts for the purposes of staging as expounded in the analysis of an early Pinter play: The Dumb Waiter
- Authors: Thomas, Jeswinne Mary
- Date: 1999
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/193203 , vital:45309
- Description: The aim of this thesis is to promote the dramatological approach, as opposed to a literary critical one, for the analysis of dramatic texts for the purposes of staging. The reason for such a promotion is that the dramatological approach upholds the integrity of the text in interpretation for the performance text by its detailed and semiotic analysis. The focus of such an approach is on the analysis of discourse, that is a micro-proairetic approach (illuminating the extralinguistic action and interaction gained from speech events and deixis), rather than a macro-proairetic approach (that is, plot and story-line) which a literary critical approach would take into consideration. In Chapter one the focus is on the justification for the dramatological approach as well as a review of prominent literary criticism to the playwright’s work (used as an example of dramatic text in this thesis). Rather than the promotion of ordinary literary theory in relation to the need for a performance methodology, explanation for their negation is offered here. Chapter two focuses on the actual methodology of the dramatological approach. In section one of this chapter, we find that basic to dramatological methodology is the linguistic function appropriate to the dramatic: that is the semantic, rhetorical and pragmatic principles of dramatic dialogue. In addition, we find that it is a formal and systematic approach which imposes restrictions on dualisms thereby upholding the integrity of the text. Moreover, that it focuses on the “performative-deictic” character (that is extralinguistic, kinesic and indexical orientations) of the dramatic text - analysis of which is crucial for the purposes of staging. In this way, the analysis of the interpersonal, interactional and contextual areas of dramatic texts is promoted. Thus section one offers an overview of the analytical criteria appropriate to such investigation in order to illuminate dramatic discourse. Section two offers a guide to the application of the methodology, utilizing an extraction of text. Central to the application is the formation of a preliminary analytical ‘grid’ from the range of criteria discussed in section one; that is, how these may be put together. A micro-segmentation of text is utilized to illustrate the application of the methodology. Chapter three offers an application of the methodology to a whole text, that is The Dumb Waiter. The results and benefits for the theatre practitioner of such application are directly illustrated in the deictic (that is section one) and proairetic (that is section two) segmentations of the text since what the text and discourse signify is illustrated in a detailed manner as opposed to paraphrase. That is, the interpersonal, contextual and interactional levels of the drama are defined. From this, typologies of discourse, character and interrelationships are drawn, as well as a creation of the dramatic world (that is section three) constructed as a result of the discourse, interrelationships and dramatic action. Finally the Conclusion offers an evaluation of the dramatological approach by applying it to a practical situation for the theatre practitioner (that is, director or actor). , Thesis (MA) -- Faculty of Humanities, Drama, 1999
- Full Text:
- Date Issued: 1999
Transformational leadership and organisational effectiveness in the administration of cricket in South Africa
- Authors: Amos, Trevor L
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/270958 , vital:54495 , xlink:href="https://hdl.handle.net/10520/EJC-682622887"
- Description: After years of isolation from the international sporting arena, South African sports teams have recently achieved much success. This article is concerned specifically with managing for organisational effectiveness in South African cricket According to the theory of transformational leadership, there should be a positive relationship between this style of leadership and organisational effectiveness. The Multifactor Leadership Questionnaire was used to collect information about leadership while data for organisational effectiveness, the dependent variable, was collected using the Effectiveness Survey for Cricket Administration. Most of the results regarding the relationship of the transformational leadership factors and organisational effectiveness were significant. On the other hand, most of the results regarding the relationship of the transactional leadership factors and organisational effectiveness were not significant. The overall results provide general support of Bass' (1990) argument of the universal application of the transformational leadership theory.
- Full Text:
- Date Issued: 1999
Applications of camphor-derived chiral auxiliaries in the asymmetric synthesis of α-amino acids and other systems
- Authors: Matjila, Joseph Moemise
- Date: 1998-04
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/191501 , vital:45106
- Description: A viable synthetic route to camphor-derived imino lactones as precursors for the asymmetric synthesis of a-amino acids has been established. Several synthetic strategies have been investigated and the required regioisomeric imino lactones were finally obtained via the step-wise condensation of JV-(carbobenzyloxy)glycine with the a-ketols, 3-exo-hydroxycamphor and 2-exo- hydroxy-3-bomanone. Enolates of the camphor imino lactones, generated using potassium tert- butoxide, were reacted with a range of alkyl halides. Dialkylation was observed using the 2-imino lactone, while the regioisomeric 3-imino lactone derivative gave monoalkylated products with diastereoselectivities, shown by NMR spectroscopy, to range from 43% d.e. for the methylated product to > 99% d.e. for larger alkyl groups. The expected preference for endo-alkylation is supported by NMR (chemical shift, coupling constant and NOE) data and was confirmed by acidic hydrolysis of the pentylated 3-imino lactone to afford the known acid. Computer modelling, with the software package HYPERCHEM®, was used to explore the conformational properties of the alkylated products and their enolate precursors. Exploratory work on the enantiomeric beneficiation of racemic amino acids, using alkylated imino lactone derivatives, revealed preferential exo-protonation of the enolate intermediates. Asymmetric Baylis-Hillman reactions between a novel camphor-derived acrylic ester and a range of aldehydes afforded the corresponding 2-(hydroxyalkyl)acrylates in up to 59% d.e., the observed stereoselectivities being sensitive to both steric and electronic factors. Attempts to prepare imino lactone derivatives from ketopinic acid, although unsuccessful, led to the isolation of two novel W-(carbobenzyloxy)glycinates, whose structures were established by 1- and 2-D NMR spectroscopy. Attempts to prepare "BINAP" analogues from dibomyl ether's also proved unsuccessful, but the investigation led to the discovery of a third, novel dibomyl ether. , Thesis (PhD) -- Faculty of Science, Chemistry, 1998
- Full Text:
- Date Issued: 1998-04
In vitro release of amoxycillin from lipophilic suppositories
- Authors: Webster, Jessica A , Dowse, Roslind , Walker, Roderick B
- Date: 1998
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184377 , vital:44213 , xlink:href="https://doi.org/10.3109/03639049809085636"
- Description: The in vitro release characteristics of amoxycillin from different lipophilic suppository bases were investigated using the USP rotating basket method. Suppositories containing 250 mg amoxycillin were prepared in theobroma oil and in the semisynthetic bases Witepsol W35, Suppocire A32, Novata BD, and Novata 299. Both freshly prepared and 1-month-old suppositories were tested. Analysis of amoxycillin was performed using a validated high-performance liquid chromatographic (HPLC) technique. Release profiles differed significantly between bases, with the greatest amount of amoxycillin being released from both newly made and 1-month-old Novata BD bases (87.57 ± 8.18 and 99.66 ± 6.63%, respectively), and the lowest amount released from the newly manufactured theobroma suppositories (8.82 ± 0.75%) and the 1-month-old Suppocire A32 suppositories (7.78 ± 0.27%).
- Full Text:
- Date Issued: 1998
Interaction of nitric oxide with cobalt (II) phthalocyanine
- Authors: Vilakazi, Sibulelo L , Nyokong, Tebello
- Date: 1998
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293579 , vital:57100 , xlink:href="https://doi.org/10.1016/S0277-5387(98)00244-7"
- Description: The coordination of nitric oxide (NO) to cobalt(II) phthalocyanine (CoPc) in dimethyl sulphoxide (DMSO) has been studied. CoPc coordinates with NO in a 1:1 ratio, forming a CoPc(NO) species. The IR band observed at 1680 cm−1 is assigned to the coordinated NO. In the presence of excess NO, pseudo first order kinetics were followed. The observed rate constant, kf, was determined to be 15.0±0.3 dm−3 mol−1 s−1 and the equilibrium constant was K=5.4±0.4×104dm3 mol−1. Solution or adsorbed CoPc catalyses the reduction of NO. The products of reduction include NH3 and NH2OH.
- Full Text:
- Date Issued: 1998