The development of ionic zinc(II) phthalocyanines for sono-photodynamic combination therapy of cervical and breast cancer
- Authors: Nene, Lindokuhle Cindy
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422565 , vital:71958 , DOI 10.21504/10962/422565
- Description: This study focuses on the development of the sono-photodynamic combination therapy (SPDT) activity of phthalocyanines (Pcs) on the cervical and breast cancer cell lines in vitro. The SPDT technique utilizes ultrasound in combination with light to elicit cytotoxic effects for cancer eradication. In this work, a selection of tetra-peripherally substituted Zn(II) cationic and zwitterionic Pcs were prepared. The photophysical parameters of the Pcs were determined including their fluorescence behaviours and efficiency of the triplet excited state population. The effects of the ultrasonic parameters (frequencies (MHz) and power (W.cm-2)) on the stability of the Pcs were evaluated. Four parameters were evaluated: Par I (1 MHz: 1 W.cm-2), Par II (1 MHz: 2 W.cm-2), Par III (3 MHz: 1 W.cm-2) and Par IV (3 MHz: 2 W.cm-2). The stability of the Pcs reduced with the increase in the ultrasonic power (for Par II and Par IV). The Par I showed the least degradation compared to the other parameters and was therefore used for the SPDT treatments. The sonodynamic (SDT), photodynamic (PDT) therapy activities of the Pcs were studied and compared to their SPDT efficacies. The Pcs showed reactive oxygen species generation during the SDT, PDT and SPDT treatments. For the SDT and SPDT, singlet oxygen (1O2) and hydroxyl radicals (•OH) were detected. For PDT, only the 1O2 were detected. The cell cytotoxicity studies for the Pcs showed relatively higher therapeutic efficacies for the SDT treatments compared to the PDT treatments, where the SPDT showed higher therapeutic efficacies compared to both the SDT and PDT monotreatments on both the cell lines in vitro. Overall, the combination treatments were better compared to the monotreatments. The activities of the Pcs were compared by their differences in structures, including the type of R-group, type of quaternizing agent and type of nanoparticle conjugates. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
- Full Text:
- Date Issued: 2023-03-31
Social media influence on graduateness skills and employability: the case of historically disadvantaged institutions.
- Authors: Murire, Obrain T
- Date: 2021-09
- Subjects: Social media--Influence
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20383 , vital:45660
- Description: Orientation: The graduate labour force is increasing as more students are graduating from historically disadvantaged institutions (HDIs). The lack of graduateness attributes amongst final year students has in part contributed to the high rate of graduate unemployment in South Africa. Social media have been identified as a solution as more than 95percent of young adults enrolled at historically disadvantaged institutions in South Africa are using mobile technology. Research Purpose: The purpose of the study was to develop a model to enhance graduateness skills and employability through the use of social media amongst final year students at HDIs in the Eastern Cape Province of South Africa. Motivation for the study: The study is of utmost importance as it has developed an artefact that investigated the influence of social media use on graduateness skills and employability amongst students at HDIs in the Eastern Cape Province of South Africa. Additionally, students at HDIs are an interesting theoretical sample due to them being an under-researched sample. The HDIs context has received scant focus and attention. In theory, the link between psychological constructs (such as graduateness skills and employability) with a technology dimension especially within our South African context and internationally remains unexplored. Research approach/design and method: Social Media Integration and Career EDGE models were used as a theoretical foundation in this study. This study adopted design science as a research method, where a mixed-method technique was used to collect data from final year students and human resource practitioners. The sequential exploratory design was chosen as it offers an iterative process of developing an artefact that can be tested within a larger population. The questionnaire for interviews and the survey were developed after a thorough literature review and pilot study had been conducted. The questionnaire was distributed to all the participants, of which 411 responded, resulting in a response rate of 93percent; and 15 interviews were conducted. Descriptive statistics were used to analyse the data and correlations test were used to determine associations between variables. Main findings: The study found that there is a significant direct effect of social media use on graduateness skills; there is a significant direct effect of graduateness skills on perceived employability. Graduateness skills have a significant mediating effect on the relationship between social media use and perceived employability. The results also revealed that the direct effect of social media use on perceived employability does not exist. Practical/managerial implications: The study shows that there is a need for the government to devise policies that set guidelines for HR practitioners to follow when recruiting and selecting graduates. Contribution/value-add: The research study contributes to the growing body of research as it utilised a mixed-method approach to explore lived experiences. The Graduate Employability Social Media Model (GESM Model) is the main contribution made by this study to the body of knowledge in both the fields of Information Systems and Business Management. , Thesis (PhD) (Information Systems) -- University of Fort Hare, 2021.
- Full Text:
- Date Issued: 2021-09