Mechanistic analysis of two cytotoxic thiazolidinones as novel inhibitors of Triple-Negative Breast Cancer
- Authors: Vukea, Nyeleti
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365734 , vital:65780
- Description: Thesis embargoes. Expected release date early 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Vukea, Nyeleti
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365734 , vital:65780
- Description: Thesis embargoes. Expected release date early 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
Development of biosensor systems for the detection of anti-cancer drugs and prostate cancer
- Authors: Mwanza, Daniel
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365929 , vital:65803
- Description: Thesis embargoed. Expected release date early 2025. , Thesis (PhD) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Mwanza, Daniel
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365929 , vital:65803
- Description: Thesis embargoed. Expected release date early 2025. , Thesis (PhD) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Date Issued: 2022-10-14
Regulation of Oct4 expression during cell stress
- Authors: Samson, William John
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365712 , vital:65778
- Description: Thesis embargoed. Expected release date early 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Samson, William John
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365712 , vital:65778
- Description: Thesis embargoed. Expected release date early 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
Country risk and stock market volatility in Africa: Measuring the contribution of political and economic risk factors
- Authors: Hoveni, Jamela Basani
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/405445 , vital:70172
- Description: Thesis embargoed. To be released in 2025. , Thesis (PhD) -- Faculty of Commerce, Economics and economic History, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Hoveni, Jamela Basani
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/405445 , vital:70172
- Description: Thesis embargoed. To be released in 2025. , Thesis (PhD) -- Faculty of Commerce, Economics and economic History, 2022
- Full Text:
- Date Issued: 2022-10-14
Characterisation of two novel ferrocenyl benzoxazines as in vitro triple-negative breast cancer inhibitors
- Authors: Mhlanga, Richwell
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365689 , vital:65776
- Description: Thesis access embargoed. Expected released date early 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Mhlanga, Richwell
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365689 , vital:65776
- Description: Thesis access embargoed. Expected released date early 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
Identification and characterisation of microbial communities and their metabolic potential in meltwater ponds, Western Dronning Mau Land, Antarctica
- Authors: Van Aswegen, Sunet
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365723 , vital:65779
- Description: Thesis embargoed. Expected release date early 2024. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Van Aswegen, Sunet
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365723 , vital:65779
- Description: Thesis embargoed. Expected release date early 2024. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
Dual and targeted photodynamic therapy ablation of bacterial and cancer cells using phthalocyanines and porphyrins in the presence of carbon-based nanomaterials
- Authors: Openda, Yolande Ikala
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365945 , vital:65804 , DOI https://doi.org/10.21504/10962//365946
- Description: Phthalocyanines (Pcs) and porphyrins bearing substituents that possess antibacterial/anticancer properties are used as photosensitizers (PS) for the first time in the work. For targeting specificity and improved photoactivity, the PSs were afterward functionalized with carbon nanomaterials such as graphene quantum dots (GQDs) and detonation nanodiamonds (DNDs) via covalent conjugation (amide or ester bonds) or by non-covalent conjugation (π-π stacking and electrostatic interactions). Furthermore, the PSs-DNDs nanoconjugates were conjugated to either chitosan-capped silver nanoparticles (CSAg) via amide bonds or to the bare silver nanoparticles (Ag NPs) using the silver- nitrogen affinity. The as-synthesized nanoconjugates were also fully characterized by spectroscopic and microscopic methods together with thermal analysis. The potential photocytotoxicity of the complexes alone and their nanoconjugates against S. aureus and/or E. coli planktonic and biofilm cultures has been evaluated in vitro. Compared to the non- quaternized PSs, the cationic analogs exhibited a higher photodynamic inactivation against the planktonic cells with log10 reduction values above 9 in the viable count using a concentration of ca. 1.25 μM following 30 min exposure to light (Light dose: 943 J/cm2 for Pcs and 250 mW/cm2 for porphyrins). Whereas, at a concentration of ca. 100 μM the cationic PSs showed complete eradication of biofilms upon 30 min exposure to light. As a result of conjugation to carbon-based nanomaterials and silver nanoparticles, the compounds proved to be more effective as they exhibited stronger antibacterial and anti-biofilm activities on the multi-drug resistant bacteria strains due to synergetic effect, compared to PSs alone. This suggests that the newly prepared nanohybrids (PS concentration ca. 100 μM) could be used as potential antimicrobial agents in the treatment of biofilm-related infections. The target nanoconjugates showed all the advantages of two different groups existing on a single entity. In light of the potential advantages of combined chemotherapy and photodynamic antimicrobial chemotherapy (PACT), this work reports for the first time the use of PACT-ciprofloxacin (CIP) dual therapy using selected indium quaternized PSs which showed higher photoactivity with complete eradication of both Gram-positive and Gram-negative bacteria biofilms at concentrations of 8 μM of PS versus 2 μg/mL of the antibiotic following 15 min irradiation time (light dose: 471 J/cm2 for Pcs and fluence: 250 mW/cm2 for porphyrins) on S. aureus. Whereas the total killing of E. coli was obtained when combining 8 or 16 μM of PS combined with 4 μg/mL of CIP. The combined treatment resulted in the complete eradication of the matured biofilms with the highest log10 reduction values of 7.05 and 7.20 on S. aureus and E. coli, respectively. Used as a model, positively charged dimethylamino-chalcone Pcs also exhibited interesting photodynamic therapy (PDT) activity against MCF-7 cancer cells giving IC50 values of 17.9 and 7.4 μM, respectively following 15 min irradiation. Additionally, the TD-B3LYP/LanL2DZ calculations were run on the dimethylaminophenyl- porphyrins to compare the singlet excitation energies of quaternized and non-quaternized porphyrins in vacuo. the study shows excellent agreement between time-dependent density- functional theory (TD-DFT) exciting energies and the experimental S1>S0 excitation energies. The small deviation observed between the calculated and experimental spectra arises from the solvent effect. The excitation energies observed in these UV-Vis spectra mostly originated from electron promotion between the highest occupied molecular orbital (HOMO) for the less intense band and the HOMO-1 for the most intense band of the ground states to the lower unoccupied molecular orbital (LUMO) of the excited states. , Thesis (PhD) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Openda, Yolande Ikala
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365945 , vital:65804 , DOI https://doi.org/10.21504/10962//365946
- Description: Phthalocyanines (Pcs) and porphyrins bearing substituents that possess antibacterial/anticancer properties are used as photosensitizers (PS) for the first time in the work. For targeting specificity and improved photoactivity, the PSs were afterward functionalized with carbon nanomaterials such as graphene quantum dots (GQDs) and detonation nanodiamonds (DNDs) via covalent conjugation (amide or ester bonds) or by non-covalent conjugation (π-π stacking and electrostatic interactions). Furthermore, the PSs-DNDs nanoconjugates were conjugated to either chitosan-capped silver nanoparticles (CSAg) via amide bonds or to the bare silver nanoparticles (Ag NPs) using the silver- nitrogen affinity. The as-synthesized nanoconjugates were also fully characterized by spectroscopic and microscopic methods together with thermal analysis. The potential photocytotoxicity of the complexes alone and their nanoconjugates against S. aureus and/or E. coli planktonic and biofilm cultures has been evaluated in vitro. Compared to the non- quaternized PSs, the cationic analogs exhibited a higher photodynamic inactivation against the planktonic cells with log10 reduction values above 9 in the viable count using a concentration of ca. 1.25 μM following 30 min exposure to light (Light dose: 943 J/cm2 for Pcs and 250 mW/cm2 for porphyrins). Whereas, at a concentration of ca. 100 μM the cationic PSs showed complete eradication of biofilms upon 30 min exposure to light. As a result of conjugation to carbon-based nanomaterials and silver nanoparticles, the compounds proved to be more effective as they exhibited stronger antibacterial and anti-biofilm activities on the multi-drug resistant bacteria strains due to synergetic effect, compared to PSs alone. This suggests that the newly prepared nanohybrids (PS concentration ca. 100 μM) could be used as potential antimicrobial agents in the treatment of biofilm-related infections. The target nanoconjugates showed all the advantages of two different groups existing on a single entity. In light of the potential advantages of combined chemotherapy and photodynamic antimicrobial chemotherapy (PACT), this work reports for the first time the use of PACT-ciprofloxacin (CIP) dual therapy using selected indium quaternized PSs which showed higher photoactivity with complete eradication of both Gram-positive and Gram-negative bacteria biofilms at concentrations of 8 μM of PS versus 2 μg/mL of the antibiotic following 15 min irradiation time (light dose: 471 J/cm2 for Pcs and fluence: 250 mW/cm2 for porphyrins) on S. aureus. Whereas the total killing of E. coli was obtained when combining 8 or 16 μM of PS combined with 4 μg/mL of CIP. The combined treatment resulted in the complete eradication of the matured biofilms with the highest log10 reduction values of 7.05 and 7.20 on S. aureus and E. coli, respectively. Used as a model, positively charged dimethylamino-chalcone Pcs also exhibited interesting photodynamic therapy (PDT) activity against MCF-7 cancer cells giving IC50 values of 17.9 and 7.4 μM, respectively following 15 min irradiation. Additionally, the TD-B3LYP/LanL2DZ calculations were run on the dimethylaminophenyl- porphyrins to compare the singlet excitation energies of quaternized and non-quaternized porphyrins in vacuo. the study shows excellent agreement between time-dependent density- functional theory (TD-DFT) exciting energies and the experimental S1>S0 excitation energies. The small deviation observed between the calculated and experimental spectra arises from the solvent effect. The excitation energies observed in these UV-Vis spectra mostly originated from electron promotion between the highest occupied molecular orbital (HOMO) for the less intense band and the HOMO-1 for the most intense band of the ground states to the lower unoccupied molecular orbital (LUMO) of the excited states. , Thesis (PhD) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Date Issued: 2022-10-14
Socio-historical analysis of organisational change: a case study of Zimbabwe Posts (Zimpost), 2010–2020
- Kambarami-Zengeni, Faith Chipo
- Authors: Kambarami-Zengeni, Faith Chipo
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422518 , vital:71954 , DOI 10.21504/10962/422518
- Description: Postal organisations play an important role in the provision of basic communication services. In Zimbabwe, post offices have a large physical distribution network of over 240 post offices country-wide to make communication services accessible to the populace. However, e-substitution has threatened mail business significantly. Postal operators globally are experiencing declining mail volumes in the face of advanced information and communication technologies. The overall goal of this thesis was to undertake a socio-historical analysis of organisational change at ZimPost using Taylorism, Fordism and post-Fordism as broad ideal types to explain how industry evolves in different phases of capitalism. National politics and economics play an integral role in how Taylorism, Fordism and post-Fordism assumed at ZimPost. Studies on these broad organising types have mainly focused on private sector organisations. However, this thesis argues that these analytical paradigms are also valid in public sector organisations, but they will unfold differently given the context in which change is experienced. Using a qualitative approach, the study established that the 1980s and 1990s can best be described as the ‘golden years’ of postal services in Zimbabwe, characterised by mass production and mass consumption of postal products and services. At that time the Posts and Telecommunications Corporation enjoyed a monopoly of postal services in the country. The stable market share, competitive salaries for postal workers, increased unionisation and a fairly stable economy enabled a Fordist regime of accumulation to develop. The cycle broke down when the mode of regulation was weakened by national economic and political changes towards the late 1990s. PTC started to experience a decline in the consumption of postal products. The decline was also attributed to increased competition from smaller private courier operators that could provide specialised services to a market with changing needs. With increased competition, the advancement of information, and communication technologies, mail volumes dwindled. This period can best be described as the crisis of Fordism at ZimPost. In the year 2000, the government unbundled the posts and telecommunications corporation to create four companies including Zimbabwe Posts. This was perceived as one of the most radical organisational changes in the history of postal services in Zimbabwe. More organisational changes took place at ZimPost that can best be described as characteristics of post-Fordism. These changes were attempts by ZimPost to remain relevant in light of the economic, political and technological changes taking place in the country. The postal operator introduced customised products in the form of agency services, supported by increased use of information and communication technologies in the post office. Organisational changes at ZimPost were shaped mainly by the economic and political environment in which they took place. Organisational change is complex, changes do not follow a linear pattern, they are processual. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2023
- Full Text:
- Date Issued: 2022-10-14
- Authors: Kambarami-Zengeni, Faith Chipo
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422518 , vital:71954 , DOI 10.21504/10962/422518
- Description: Postal organisations play an important role in the provision of basic communication services. In Zimbabwe, post offices have a large physical distribution network of over 240 post offices country-wide to make communication services accessible to the populace. However, e-substitution has threatened mail business significantly. Postal operators globally are experiencing declining mail volumes in the face of advanced information and communication technologies. The overall goal of this thesis was to undertake a socio-historical analysis of organisational change at ZimPost using Taylorism, Fordism and post-Fordism as broad ideal types to explain how industry evolves in different phases of capitalism. National politics and economics play an integral role in how Taylorism, Fordism and post-Fordism assumed at ZimPost. Studies on these broad organising types have mainly focused on private sector organisations. However, this thesis argues that these analytical paradigms are also valid in public sector organisations, but they will unfold differently given the context in which change is experienced. Using a qualitative approach, the study established that the 1980s and 1990s can best be described as the ‘golden years’ of postal services in Zimbabwe, characterised by mass production and mass consumption of postal products and services. At that time the Posts and Telecommunications Corporation enjoyed a monopoly of postal services in the country. The stable market share, competitive salaries for postal workers, increased unionisation and a fairly stable economy enabled a Fordist regime of accumulation to develop. The cycle broke down when the mode of regulation was weakened by national economic and political changes towards the late 1990s. PTC started to experience a decline in the consumption of postal products. The decline was also attributed to increased competition from smaller private courier operators that could provide specialised services to a market with changing needs. With increased competition, the advancement of information, and communication technologies, mail volumes dwindled. This period can best be described as the crisis of Fordism at ZimPost. In the year 2000, the government unbundled the posts and telecommunications corporation to create four companies including Zimbabwe Posts. This was perceived as one of the most radical organisational changes in the history of postal services in Zimbabwe. More organisational changes took place at ZimPost that can best be described as characteristics of post-Fordism. These changes were attempts by ZimPost to remain relevant in light of the economic, political and technological changes taking place in the country. The postal operator introduced customised products in the form of agency services, supported by increased use of information and communication technologies in the post office. Organisational changes at ZimPost were shaped mainly by the economic and political environment in which they took place. Organisational change is complex, changes do not follow a linear pattern, they are processual. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2023
- Full Text:
- Date Issued: 2022-10-14
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