In vitro cytotoxic effects of chemical constituents of Euphorbia grandicornis Blanc against breast cancer cells
- Kemboi, Douglas, Peter, Xolani, Langat, Moses K, Mhlanga, Richwell, Vukea, Nyeleti, de la Mare, Jo-Anne, Siwe-Noundou, Xavier, Krause, Rui W M, Tembu, Vuyelwa J
- Authors: Kemboi, Douglas , Peter, Xolani , Langat, Moses K , Mhlanga, Richwell , Vukea, Nyeleti , de la Mare, Jo-Anne , Siwe-Noundou, Xavier , Krause, Rui W M , Tembu, Vuyelwa J
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/191747 , vital:45160 , xlink:href="https://doi.org/10.1016/j.sciaf.2021.e01002"
- Description: Euphorbia grandicornis Blanc is widely utilized in traditional medicine for a variety of ailments including body pains associated with skin irritations, inflammation, and snake or scorpion bites. Compounds from E. grandicornis were characterized using spectroscopic techniques, NMR, IR, MS, and melting points and alongside the extracts were evaluated for in vitro anticancer activity against several cancer cell lines. The root extract afforded known, β-glutinol (1), β-amyrin (2), 24-methylenetirucalla-8-en-3β-ol (3), tirucalla-8,25-diene-3β,24R-diol (4), stigmasterol (5), sitosterol (6), and hexyl (E)-3-(4-hydroxy-3-methoxyphenyl)-2-propenoate (7) based on their NMR spectroscopic data for the first report in E. grandicornis. The extracts and isolated compounds were evaluated for anticancer activities against hormone receptor-positive breast cancer (MCF-7), triple-negative breast cancer (HCC70), and non-tumorigenic mammary epithelial (MCF-12A) cell lines. The CH2Cl2 extract exhibited potent, cytotoxicity against MCF-7, HCC70, and MCF-12A cells. The aerial extract exhibited IC50 values of 1.03, 0.301, and 1.68 µg/mL, and root extract displayed IC50 values of 0.83, 0.83 and 3.98 µg/mL against MCF-7, HCC70, and MCF-12A cells respectively. The root extract thus showed selectivity for the cancer cell lines over the non-cancerous control cell line (SI = 4.80). Hexyl (E)-3-(4-hydroxy-3-methoxyphenyl)-2-propenoate (7) showed significant activity with IC50 values of 23.41, 29.45 and 27.01 µM against MCF-7, HCC70 and MCF-12A cells respectively, suggesting non-specific cytotoxicity.
- Full Text:
- Date Issued: 2021
- Authors: Kemboi, Douglas , Peter, Xolani , Langat, Moses K , Mhlanga, Richwell , Vukea, Nyeleti , de la Mare, Jo-Anne , Siwe-Noundou, Xavier , Krause, Rui W M , Tembu, Vuyelwa J
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/191747 , vital:45160 , xlink:href="https://doi.org/10.1016/j.sciaf.2021.e01002"
- Description: Euphorbia grandicornis Blanc is widely utilized in traditional medicine for a variety of ailments including body pains associated with skin irritations, inflammation, and snake or scorpion bites. Compounds from E. grandicornis were characterized using spectroscopic techniques, NMR, IR, MS, and melting points and alongside the extracts were evaluated for in vitro anticancer activity against several cancer cell lines. The root extract afforded known, β-glutinol (1), β-amyrin (2), 24-methylenetirucalla-8-en-3β-ol (3), tirucalla-8,25-diene-3β,24R-diol (4), stigmasterol (5), sitosterol (6), and hexyl (E)-3-(4-hydroxy-3-methoxyphenyl)-2-propenoate (7) based on their NMR spectroscopic data for the first report in E. grandicornis. The extracts and isolated compounds were evaluated for anticancer activities against hormone receptor-positive breast cancer (MCF-7), triple-negative breast cancer (HCC70), and non-tumorigenic mammary epithelial (MCF-12A) cell lines. The CH2Cl2 extract exhibited potent, cytotoxicity against MCF-7, HCC70, and MCF-12A cells. The aerial extract exhibited IC50 values of 1.03, 0.301, and 1.68 µg/mL, and root extract displayed IC50 values of 0.83, 0.83 and 3.98 µg/mL against MCF-7, HCC70, and MCF-12A cells respectively. The root extract thus showed selectivity for the cancer cell lines over the non-cancerous control cell line (SI = 4.80). Hexyl (E)-3-(4-hydroxy-3-methoxyphenyl)-2-propenoate (7) showed significant activity with IC50 values of 23.41, 29.45 and 27.01 µM against MCF-7, HCC70 and MCF-12A cells respectively, suggesting non-specific cytotoxicity.
- Full Text:
- Date Issued: 2021
Industry 4.0 and Skills Deficiencies in the HRM Function: Case Study of the HRM Department of a selected organisation in Cape Town
- Asoba, Samson Nambei, Patricia, Nteboheng Mefi
- Authors: Asoba, Samson Nambei , Patricia, Nteboheng Mefi
- Date: 2021
- Subjects: Personel Management Industry 4.0 Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/8095 , vital:61395 , xlink:href="https://www.abacademies.org/articles/industry-40-and-skills-deficiencies-in-the-hrm-function-case-study-of-the-hrm-department-of-a-selected-organization-in-cape-town-10664.html"
- Description: The study was formulated to tap into the future of HRM given the disruptions arising from the Covid-119 pandemic as well as the progression of the global technological environment to the fourth industrial revolution. The aim of the study was to: the Covid-19 induced HRM practices underpinning future organizational competitiveness. A literature review strategy was adopted to achieve the study objective. The study established seven emerging themes to inform HRM practices for the competitiveness of organizations in future following the Covid-19 disturbances. These themes are: primacy of HRM, increased cyber influences, digitalization, remote HRM, human-machine interface skills, human-organisation strategic links as well as human-technology interface competencies. Based on the study findings, the study recommended HRM departments to move to HR 4.0 through the adoption of industry 4.0 technologies, increased automation, and digitalization as well as strengthen virtualization systems.
- Full Text:
- Date Issued: 2021
- Authors: Asoba, Samson Nambei , Patricia, Nteboheng Mefi
- Date: 2021
- Subjects: Personel Management Industry 4.0 Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/8095 , vital:61395 , xlink:href="https://www.abacademies.org/articles/industry-40-and-skills-deficiencies-in-the-hrm-function-case-study-of-the-hrm-department-of-a-selected-organization-in-cape-town-10664.html"
- Description: The study was formulated to tap into the future of HRM given the disruptions arising from the Covid-119 pandemic as well as the progression of the global technological environment to the fourth industrial revolution. The aim of the study was to: the Covid-19 induced HRM practices underpinning future organizational competitiveness. A literature review strategy was adopted to achieve the study objective. The study established seven emerging themes to inform HRM practices for the competitiveness of organizations in future following the Covid-19 disturbances. These themes are: primacy of HRM, increased cyber influences, digitalization, remote HRM, human-machine interface skills, human-organisation strategic links as well as human-technology interface competencies. Based on the study findings, the study recommended HRM departments to move to HR 4.0 through the adoption of industry 4.0 technologies, increased automation, and digitalization as well as strengthen virtualization systems.
- Full Text:
- Date Issued: 2021
Institutionalised business incubation: a frontier for accelerating entrepreneurship in African countries
- Authors: Lose, Thobekani
- Date: 2021
- Subjects: Economic indicators , Economic growth , Business incubators
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7405 , vital:53977 , https://www.abacademies.org/articles/institutionalised-business-incubation-a-frontier-for-accelerating-entrepreneurship-in-african-countries-9989.html
- Description: Africa is a growing hub for small, medium and large enterprise. This paper attempts to cement the need to create business incubation institutions in South Africa (as well as in other African countries) so as to promote a superior entrepreneurial ecosystem for economic growth. The Africa of tomorrow needs solutions that last and one key component is the progress of entrepreneurship as an employment strategy, an innovation and creativity platform, and a key economic factor. This study employs a narrative overview of literature to explore an institutionalised business incubation concept as a frontier for accelerating entrepreneurship in African countries. The study found that the need for institutionalised business incubation has become pervasive for superior entrepreneurial ecosystems across economies. The study recommends that central governments need to promote the development of local, regional and national institutions for the strong development of incubation as well as entrepreneurship.
- Full Text:
- Date Issued: 2021
- Authors: Lose, Thobekani
- Date: 2021
- Subjects: Economic indicators , Economic growth , Business incubators
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7405 , vital:53977 , https://www.abacademies.org/articles/institutionalised-business-incubation-a-frontier-for-accelerating-entrepreneurship-in-african-countries-9989.html
- Description: Africa is a growing hub for small, medium and large enterprise. This paper attempts to cement the need to create business incubation institutions in South Africa (as well as in other African countries) so as to promote a superior entrepreneurial ecosystem for economic growth. The Africa of tomorrow needs solutions that last and one key component is the progress of entrepreneurship as an employment strategy, an innovation and creativity platform, and a key economic factor. This study employs a narrative overview of literature to explore an institutionalised business incubation concept as a frontier for accelerating entrepreneurship in African countries. The study found that the need for institutionalised business incubation has become pervasive for superior entrepreneurial ecosystems across economies. The study recommends that central governments need to promote the development of local, regional and national institutions for the strong development of incubation as well as entrepreneurship.
- Full Text:
- Date Issued: 2021
Knowledge of formal and informal regulations affecting wild plant foraging practices in urban spaces in South Africa
- Garekae, Hesekia, Shackleton, Charlie M
- Authors: Garekae, Hesekia , Shackleton, Charlie M
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/403221 , vital:69935 , xlink:href="https://doi.org/10.1016/j.forpol.2021.102659"
- Description: Although foraging wild plants is commonly perceived to be synonymous with rural areas, it is now increasingly recognized in urban areas. Notwithstanding, the regulations conditioning access to and rights to foraging in urban green spaces have seldom been examined. This study explored the formal and informal regulations governing access to and defining rights to forageable plant resources in the towns of Potchefstroom and Thabazimbi, South Africa. A random sample of 374 households was considered for the survey, complemented by in-depth interviews with 26 participants. Foraging occurred in a variety of public and private spaces, with the frequency of access differing with the type of space. The majority of the respondents were unaware of formal and informal regulations governing access to and use of urban landscapes. Recognizing foraging activities in urban landscapes is a fundamental step toward fostering active community involvement in the management and production of urban green spaces.
- Full Text:
- Date Issued: 2021
- Authors: Garekae, Hesekia , Shackleton, Charlie M
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/403221 , vital:69935 , xlink:href="https://doi.org/10.1016/j.forpol.2021.102659"
- Description: Although foraging wild plants is commonly perceived to be synonymous with rural areas, it is now increasingly recognized in urban areas. Notwithstanding, the regulations conditioning access to and rights to foraging in urban green spaces have seldom been examined. This study explored the formal and informal regulations governing access to and defining rights to forageable plant resources in the towns of Potchefstroom and Thabazimbi, South Africa. A random sample of 374 households was considered for the survey, complemented by in-depth interviews with 26 participants. Foraging occurred in a variety of public and private spaces, with the frequency of access differing with the type of space. The majority of the respondents were unaware of formal and informal regulations governing access to and use of urban landscapes. Recognizing foraging activities in urban landscapes is a fundamental step toward fostering active community involvement in the management and production of urban green spaces.
- Full Text:
- Date Issued: 2021
Leadership Styles and Employee Job Satisfaction: A Case of Head of Departments in Walter Sisulu UniversityMonitoring and Management Mechanisms on Stress in HEI in Eastern Cape Province in South Africa: Critical Review
- Asoba, Samson Nambei, Patricia, Nteboheng Mefi
- Authors: Asoba, Samson Nambei , Patricia, Nteboheng Mefi
- Date: 2021
- Subjects: Educational Leadership Education (Higher) College department heads Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/8082 , vital:61392 , xlink:href="https://www.abacademies.org/articles/leadership-styles-and-employee-job-satisfaction-a-case-of-head-of-departments-in-walter-sisulu-university-10942.html"
- Description: This study was based on the relationship between the leadership styles of Academic head of Department and employee job satisfaction at the Higher Education Institution (HEI). In so doing, the study was based on the following questions: What is the relationship between leadership styles of HODs and employee job satisfaction in a Higher Education institution in the Eastern Cape Province of South Africa. A purposive sampling technique was utilised to select the participants, which comprised 80 academic staff members to which the researcher hand-delivered 80 questionnaires. The study employed a quantitative method to collect and analyse data. The study found that Perceptions on the leadership styles of academic HODs at the HEI are varied. No clear pattern emerged on what leadership styles are prevalent. The relationship between leadership styles and employee job satisfaction appears to be nonlinear. Job satisfaction is a phenomenon that is determined by many factors, not simply leadership styles.
- Full Text:
- Date Issued: 2021
- Authors: Asoba, Samson Nambei , Patricia, Nteboheng Mefi
- Date: 2021
- Subjects: Educational Leadership Education (Higher) College department heads Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/8082 , vital:61392 , xlink:href="https://www.abacademies.org/articles/leadership-styles-and-employee-job-satisfaction-a-case-of-head-of-departments-in-walter-sisulu-university-10942.html"
- Description: This study was based on the relationship between the leadership styles of Academic head of Department and employee job satisfaction at the Higher Education Institution (HEI). In so doing, the study was based on the following questions: What is the relationship between leadership styles of HODs and employee job satisfaction in a Higher Education institution in the Eastern Cape Province of South Africa. A purposive sampling technique was utilised to select the participants, which comprised 80 academic staff members to which the researcher hand-delivered 80 questionnaires. The study employed a quantitative method to collect and analyse data. The study found that Perceptions on the leadership styles of academic HODs at the HEI are varied. No clear pattern emerged on what leadership styles are prevalent. The relationship between leadership styles and employee job satisfaction appears to be nonlinear. Job satisfaction is a phenomenon that is determined by many factors, not simply leadership styles.
- Full Text:
- Date Issued: 2021
Local use and knowledge of Hyphaene coriacea and Phoenix reclinata in Zitundo area, southern Mozambique:
- Martins, Angelina R O, Shackleton, Charlie M
- Authors: Martins, Angelina R O , Shackleton, Charlie M
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175801 , vital:42625 , https://doi.org/10.1016/j.sajb.2020.12.011
- Description: Hyphaene coriacea and Phoenix reclinata are two abundant palm species in the Maputaland coastal plains of southern Mozambique. They provide an array of subsistence and commercial non- timber forest products. This research characterizes the ethnobotanical knowledge and uses of these species. Using structured interviews we assessed the knowledge, past and current uses, cultural importance and the determinants of the knowledge and current uses of these species. The knowledge about the uses of these two palms is widespread, however only 32% of respondents are engaged in palm exploitation. Thirteen palm products are used in the area with palm wine production from the sap of both species being the dominant activity, followed by broom production.
- Full Text:
- Date Issued: 2021
- Authors: Martins, Angelina R O , Shackleton, Charlie M
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175801 , vital:42625 , https://doi.org/10.1016/j.sajb.2020.12.011
- Description: Hyphaene coriacea and Phoenix reclinata are two abundant palm species in the Maputaland coastal plains of southern Mozambique. They provide an array of subsistence and commercial non- timber forest products. This research characterizes the ethnobotanical knowledge and uses of these species. Using structured interviews we assessed the knowledge, past and current uses, cultural importance and the determinants of the knowledge and current uses of these species. The knowledge about the uses of these two palms is widespread, however only 32% of respondents are engaged in palm exploitation. Thirteen palm products are used in the area with palm wine production from the sap of both species being the dominant activity, followed by broom production.
- Full Text:
- Date Issued: 2021
Low‐temperature physiology of climatically distinct south African populations of the biological control agent Neochetina eichhorniae
- Rogers, Daniel J, Terblanche, John S, Owen, Candice A
- Authors: Rogers, Daniel J , Terblanche, John S , Owen, Candice A
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444421 , vital:74239 , https://doi.org/10.1111/een.12935
- Description: Neochetina eichhorniae is the most widely established biocontrol agent on water hyacinth populations around South Africa. However, some N. eichhorniae populations have failed to adequately control their host population, specifically those exposed to cold conditions. The aim of this study was to determine whether two climatically distinct populations of N. eichhorniae in South Africa differ in their low‐temperature physiol-ogy, which tests whether local-climate adaptation has occurred.
- Full Text:
- Date Issued: 2021
- Authors: Rogers, Daniel J , Terblanche, John S , Owen, Candice A
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444421 , vital:74239 , https://doi.org/10.1111/een.12935
- Description: Neochetina eichhorniae is the most widely established biocontrol agent on water hyacinth populations around South Africa. However, some N. eichhorniae populations have failed to adequately control their host population, specifically those exposed to cold conditions. The aim of this study was to determine whether two climatically distinct populations of N. eichhorniae in South Africa differ in their low‐temperature physiol-ogy, which tests whether local-climate adaptation has occurred.
- Full Text:
- Date Issued: 2021
Macrofauna associated with intertidal mussel beds in the Knysna estuarine embayment, South Africa
- Hodgson, Alan N, Smith, Frances, Smith, Peter, Claasens, Louw
- Authors: Hodgson, Alan N , Smith, Frances , Smith, Peter , Claasens, Louw
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443554 , vital:74131 , https://hdl.handle.net/10520/ejc-afzoo_v56_i1_a44
- Description: The alien invasive mussel, Mytilus galloprovincialis, forms biogenic habitats in the embayment of Knysna Estuary. Invertebrate macrofauna inhabiting mussel beds were sampled from six sites in the embayment. In addition, mussel cover, mussel bed depth, density and size of mussels were recorded. With the exception of two sites (The Heads and Featherbed) where some Perna perna was present, we confirmed that the mussel beds were composed of the invasive species M. galloprovincialis. At The Heads, mussel beds were single-layered and in patches, whereas at other sites they were multi-layered with 100% cover. Bed depth, mussel density and shell size varied among sites. A total of 65 taxa (mainly Crustacea and Mollusca) were identified across all sites with species richness and diversity being significantly different among sites. Forty-three percent of taxa were new records for the estuary. Macrofaunal richness and diversity were highest at the two sites (The Heads and Featherbed) closest to the mouth of the embayment. There were negative relationships between species diversity and mussel density, and diversity and macroinvertebrate abundance. At most sites macrofaunal abundance was dominated by one or two species. Multivariate analysis revealed a significant difference in species composition among sites. Where wave action was present (The Heads, Featherbed and Leisure Isle) only a few deposit feeders were present in the mussel beds. At sites where wave action was minimal (Thesen Wharf, Marina and Railway Bridge) fine silt was present in the mussel matrix and there was an increase in the number of deposit feeding species.
- Full Text:
- Date Issued: 2021
- Authors: Hodgson, Alan N , Smith, Frances , Smith, Peter , Claasens, Louw
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443554 , vital:74131 , https://hdl.handle.net/10520/ejc-afzoo_v56_i1_a44
- Description: The alien invasive mussel, Mytilus galloprovincialis, forms biogenic habitats in the embayment of Knysna Estuary. Invertebrate macrofauna inhabiting mussel beds were sampled from six sites in the embayment. In addition, mussel cover, mussel bed depth, density and size of mussels were recorded. With the exception of two sites (The Heads and Featherbed) where some Perna perna was present, we confirmed that the mussel beds were composed of the invasive species M. galloprovincialis. At The Heads, mussel beds were single-layered and in patches, whereas at other sites they were multi-layered with 100% cover. Bed depth, mussel density and shell size varied among sites. A total of 65 taxa (mainly Crustacea and Mollusca) were identified across all sites with species richness and diversity being significantly different among sites. Forty-three percent of taxa were new records for the estuary. Macrofaunal richness and diversity were highest at the two sites (The Heads and Featherbed) closest to the mouth of the embayment. There were negative relationships between species diversity and mussel density, and diversity and macroinvertebrate abundance. At most sites macrofaunal abundance was dominated by one or two species. Multivariate analysis revealed a significant difference in species composition among sites. Where wave action was present (The Heads, Featherbed and Leisure Isle) only a few deposit feeders were present in the mussel beds. At sites where wave action was minimal (Thesen Wharf, Marina and Railway Bridge) fine silt was present in the mussel matrix and there was an increase in the number of deposit feeding species.
- Full Text:
- Date Issued: 2021
Malnutrition in children under the age of 5 years in a primary health care setting
- Kaswa, Ramprakash, Govender, Indiran, Rangiah, Selvandran, Nzaumvila, Doudou
- Authors: Kaswa, Ramprakash , Govender, Indiran , Rangiah, Selvandran , Nzaumvila, Doudou
- Date: 2021
- Subjects: Obesity Malnutrition Dietary supplements Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7260 , vital:53106 , xlink:href="https://doi.org/10.4102/safp.v63i1.5337"
- Description: In this study, we outlined the types of malnutrition amongst children, the causes of malnutrition intervention at the primary health care level and some recommendations to alleviate childhood malnutrition in South Africa. Keywords: obesity; severe acute malnutrition; individual factors; community level factors; dietary intervention.
- Full Text:
- Date Issued: 2021
- Authors: Kaswa, Ramprakash , Govender, Indiran , Rangiah, Selvandran , Nzaumvila, Doudou
- Date: 2021
- Subjects: Obesity Malnutrition Dietary supplements Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7260 , vital:53106 , xlink:href="https://doi.org/10.4102/safp.v63i1.5337"
- Description: In this study, we outlined the types of malnutrition amongst children, the causes of malnutrition intervention at the primary health care level and some recommendations to alleviate childhood malnutrition in South Africa. Keywords: obesity; severe acute malnutrition; individual factors; community level factors; dietary intervention.
- Full Text:
- Date Issued: 2021
Management approach of patients with violent and aggressive behaviour in a district hospital setting in South Africa
- Adeniyi, Oladele Vincent, Puzi, Ntandazo
- Authors: Adeniyi, Oladele Vincent , Puzi, Ntandazo
- Date: 2021
- Subjects: mental health Emergency medical services violennce Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7284 , vital:53108 , xlink:href="https://doi.org/10.4102/safp.v63i1.5393"
- Description: Background: Given the physical and mental health consequences of tobacco use amongst individuals with mental illness, it was imperative to assess the burden of tobacco use in this population. Aim: This study examined the patterns and factors associated with tobacco use in individuals attending the outpatient unit. Setting: Cecilia Makiwane Hospital Mental Health Department in Eastern Cape province, South Africa. Methods: Lifetime (ever use) use and current use of any tobacco products were examined in a cross-sectional study of 390 individuals between March and June 2020. A logistic regression was fitted to determine the correlates of lifetime and current use of any tobacco products. Results: The rates of ever use and current use of tobacco products were 59.4% and 44.6%, respectively. Of the participants interviewed, lifetime tobacco use was more prevalent amongst individuals with schizophrenia (67.9%) and cannabis-induced disorders (97.3%) and lower in those with major depressive disorders (36.1%) and bipolar and related disorders (43.5%). Men were six times more likely to have ever used or currently use tobacco products in comparison to women. Also, those who had a salaried job or owned a business were over three times more likely to have ever used or currently use tobacco products compared with those receiving government social grants. Conclusions: The prevalence of tobacco use in this study was significantly higher than the general population in the Eastern Cape. Therefore, smoking prevention and cessation interventions targeted at the general population should target this often neglected sub-population in the region. Keywords: aggressive and violent behaviour; assisted user; emergency centres; involuntary user; Mental Health Care Act.
- Full Text:
- Date Issued: 2021
- Authors: Adeniyi, Oladele Vincent , Puzi, Ntandazo
- Date: 2021
- Subjects: mental health Emergency medical services violennce Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7284 , vital:53108 , xlink:href="https://doi.org/10.4102/safp.v63i1.5393"
- Description: Background: Given the physical and mental health consequences of tobacco use amongst individuals with mental illness, it was imperative to assess the burden of tobacco use in this population. Aim: This study examined the patterns and factors associated with tobacco use in individuals attending the outpatient unit. Setting: Cecilia Makiwane Hospital Mental Health Department in Eastern Cape province, South Africa. Methods: Lifetime (ever use) use and current use of any tobacco products were examined in a cross-sectional study of 390 individuals between March and June 2020. A logistic regression was fitted to determine the correlates of lifetime and current use of any tobacco products. Results: The rates of ever use and current use of tobacco products were 59.4% and 44.6%, respectively. Of the participants interviewed, lifetime tobacco use was more prevalent amongst individuals with schizophrenia (67.9%) and cannabis-induced disorders (97.3%) and lower in those with major depressive disorders (36.1%) and bipolar and related disorders (43.5%). Men were six times more likely to have ever used or currently use tobacco products in comparison to women. Also, those who had a salaried job or owned a business were over three times more likely to have ever used or currently use tobacco products compared with those receiving government social grants. Conclusions: The prevalence of tobacco use in this study was significantly higher than the general population in the Eastern Cape. Therefore, smoking prevention and cessation interventions targeted at the general population should target this often neglected sub-population in the region. Keywords: aggressive and violent behaviour; assisted user; emergency centres; involuntary user; Mental Health Care Act.
- Full Text:
- Date Issued: 2021
Metrological framework for selecting morphological characters to identify species and estimate developmental maturity of forensically significant insect specimens
- Midgley, John M, Villet, Martin H
- Authors: Midgley, John M , Villet, Martin H
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440784 , vital:73813 , https://doi.org/10.1080/20961790.2020.1794347
- Description: Accurate age estimates of immature necrophagous insects associated with a human or animal body can provide evidence of how long the body has been dead. These estimates are based on species-specific details of the insects’ aging processes, and therefore require accurate species identification and developmental stage estimation. Many professionals who produce or use identified organisms as forensic evidence have little training in taxonomy or metrology, and appreciate the availability of formalized principles and standards for biological identification. Taxonomic identifications are usually most readily and economically made using categorical and qualitative morphological characters, but it may be necessary to use less convenient and potentially more ambiguous characters that are continuous and quantitative if two candidate species are closely related, or if identifying developmental stages within a species. Characters should be selected by criteria such as taxonomic specificity and metrological repeatability and relative error. We propose such a hierarchical framework, critique various measurements of immature insects, and suggest some standard approaches to determine the reliability of organismal identifications and measurements in estimating postmortem intervals. Relevant criteria for good characters include high repeatability (including low scope for ambiguity or parallax effects), pronounced discreteness, and small relative error in measurements. These same principles apply to individuation of unique objects in general.
- Full Text:
- Date Issued: 2021
- Authors: Midgley, John M , Villet, Martin H
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440784 , vital:73813 , https://doi.org/10.1080/20961790.2020.1794347
- Description: Accurate age estimates of immature necrophagous insects associated with a human or animal body can provide evidence of how long the body has been dead. These estimates are based on species-specific details of the insects’ aging processes, and therefore require accurate species identification and developmental stage estimation. Many professionals who produce or use identified organisms as forensic evidence have little training in taxonomy or metrology, and appreciate the availability of formalized principles and standards for biological identification. Taxonomic identifications are usually most readily and economically made using categorical and qualitative morphological characters, but it may be necessary to use less convenient and potentially more ambiguous characters that are continuous and quantitative if two candidate species are closely related, or if identifying developmental stages within a species. Characters should be selected by criteria such as taxonomic specificity and metrological repeatability and relative error. We propose such a hierarchical framework, critique various measurements of immature insects, and suggest some standard approaches to determine the reliability of organismal identifications and measurements in estimating postmortem intervals. Relevant criteria for good characters include high repeatability (including low scope for ambiguity or parallax effects), pronounced discreteness, and small relative error in measurements. These same principles apply to individuation of unique objects in general.
- Full Text:
- Date Issued: 2021
Mildly elevated thyroid-stimulating hormone is associated with endothelial dysfunction and severe preeclampsia among pregnant women with insufficient iodine intake in Eastern Cape province, South Africa
- Businge, Charles Bitamazire, Longo-Mbenza, Benjamin, Kengne, Andre Pascal
- Authors: Businge, Charles Bitamazire , Longo-Mbenza, Benjamin , Kengne, Andre Pascal
- Date: 2021
- Subjects: Preeclampsia Iodine deficiency diseases Endothelial cells Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6908 , vital:52565 , xlink:href="https://10.1080/07853890.2021.1947520"
- Description: Background Preeclampsia and hypothyroidism are associated with endothelial dysfunction. Iodine deficiency is a risk factor for subclinical hypothyroidism in pregnancy. However, there is a paucity of data on the relationship between iodine nutrition state in pregnancy, the degree of endothelial dysfunction, and the risk of preeclampsia. Methods Ninety-five normotensive pregnant women, 50 women with preeclampsia with no severe features, and 50 women with severe preeclampsia were enrolled into the current study from the maternity units of Nelson Mandela Academic Hospital and Mthatha Regional Hospitals in Eastern Cape Province, South Africa. Urinary iodine concentration (UIC), serum markers of thyroid function, aortic augmentation index, and pulse wave velocity (PWV) were compared. Results Median UIC was 167.5, 127.7, and 88.5 µg/L, respectively for normotensive pregnant women, those with preeclampsia and severe preeclampsia (p = .150). Participants with severe preeclampsia had significantly higher median thyroid-stimulating hormone (TSH) and oxidized LDL than normotensive and preeclamptic women without severe features (respectively 3.0, 2.3, and 2.3 IU/L; 1.2, 1.0, and 1.0 IU/L, p less .05). The median Aortic augmentation index was 7.5, 19.0, and 21.0 (p less .001), and the pulse wave velocity 5.1, 5.7, and 6.3, respectively for normotensive, preeclampsia, and severe preeclampsia participants (both p less .001). In linear regressions, TSH, age, and hypertensive disease were independent predictors of elevated PWV. Conclusion Upper normal-range TSH levels in women with severe preeclampsia were associated with markers of endothelial dysfunction. The low UIC and trend towards the elevation of thyroglobulin suggest that inadequate iodine intake may have increased TSH levels and indirectly caused endothelial dysfunction. Keywords: Preeclampsia, Iodine deficiency, Elevated thyroid-stimulating hormone, Pulse wave velocity, Endothelial dysfunction
- Full Text:
- Date Issued: 2021
- Authors: Businge, Charles Bitamazire , Longo-Mbenza, Benjamin , Kengne, Andre Pascal
- Date: 2021
- Subjects: Preeclampsia Iodine deficiency diseases Endothelial cells Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6908 , vital:52565 , xlink:href="https://10.1080/07853890.2021.1947520"
- Description: Background Preeclampsia and hypothyroidism are associated with endothelial dysfunction. Iodine deficiency is a risk factor for subclinical hypothyroidism in pregnancy. However, there is a paucity of data on the relationship between iodine nutrition state in pregnancy, the degree of endothelial dysfunction, and the risk of preeclampsia. Methods Ninety-five normotensive pregnant women, 50 women with preeclampsia with no severe features, and 50 women with severe preeclampsia were enrolled into the current study from the maternity units of Nelson Mandela Academic Hospital and Mthatha Regional Hospitals in Eastern Cape Province, South Africa. Urinary iodine concentration (UIC), serum markers of thyroid function, aortic augmentation index, and pulse wave velocity (PWV) were compared. Results Median UIC was 167.5, 127.7, and 88.5 µg/L, respectively for normotensive pregnant women, those with preeclampsia and severe preeclampsia (p = .150). Participants with severe preeclampsia had significantly higher median thyroid-stimulating hormone (TSH) and oxidized LDL than normotensive and preeclamptic women without severe features (respectively 3.0, 2.3, and 2.3 IU/L; 1.2, 1.0, and 1.0 IU/L, p less .05). The median Aortic augmentation index was 7.5, 19.0, and 21.0 (p less .001), and the pulse wave velocity 5.1, 5.7, and 6.3, respectively for normotensive, preeclampsia, and severe preeclampsia participants (both p less .001). In linear regressions, TSH, age, and hypertensive disease were independent predictors of elevated PWV. Conclusion Upper normal-range TSH levels in women with severe preeclampsia were associated with markers of endothelial dysfunction. The low UIC and trend towards the elevation of thyroglobulin suggest that inadequate iodine intake may have increased TSH levels and indirectly caused endothelial dysfunction. Keywords: Preeclampsia, Iodine deficiency, Elevated thyroid-stimulating hormone, Pulse wave velocity, Endothelial dysfunction
- Full Text:
- Date Issued: 2021
Mitigating the Implications of Covid 19 on the Academic Project at Walter Sisulu University in South Africa: A Proposed Framework for Emergency Remote Teaching and Learning
- Date: 2021
- Subjects: South Africa Covid-19 (deseases) Web-based instruction Education (Higher) Information technology Computer-assisted instruction Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7644 , vital:54734 , ("https://DOI:10.24085/jsaa.v9i1.1427")
- Description: Walter Sisulu University (WSU) in South Africa, like other universities worldwide, is faced with the challenges associated with the outbreak of the Covid‑19 pandemic. The challenge has changed our day‑to‑day lives, including the way we interact and conduct business. In the midst of this, WSU has had to change the way learning and teaching occurs. Traditional face‑to‑face tuition had to be adapted by moving to the online mode of teaching and learning to both minimise the time lost in the academic project and protect staff and students from the devastating effects of the virus. This article reflects the actions taken by the University and describes its pilot‑project approach to online learning and those processes it has put in place to ensure its effective implementation. While it is accepted that switching to an online mode of teaching and learning can facilitate flexibility in space and time, the reality is that the majority of students at WSU – mainly due to their geographical and socio‑economic environments – experience daily challenges ranging from poor network coverage, lack of internet connectivity, lack of electricity and other socio‑economic impediments that make online learning stressful or beyond their reach. In this article, we present a model that could be used by higher education institutions (HEIs) to respond to Covid‑19 in the short term. The proposed model is underpinned by a framework that caters for students who are readily able to access online learning, students with intermittent access to online facilities and finally, students who cannot access online education. First, we provide a brief description of online learning, highlighting the challenges presented to teaching and learning by this approach. We argue that our context and education policies present additional problems that militate against the adoption of online strategies by most HEIs. In the final instance, we present a framework that is better suited to our context and can be used during and after the lockdown. Data were collected using online questionnaires with both structured and open‑ended questions from both lecturers and students to determine their experiences with the testing project. Lastly, we draw conclusions based on the findings of the study.
- Full Text:
- Date Issued: 2021
- Date: 2021
- Subjects: South Africa Covid-19 (deseases) Web-based instruction Education (Higher) Information technology Computer-assisted instruction Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7644 , vital:54734 , ("https://DOI:10.24085/jsaa.v9i1.1427")
- Description: Walter Sisulu University (WSU) in South Africa, like other universities worldwide, is faced with the challenges associated with the outbreak of the Covid‑19 pandemic. The challenge has changed our day‑to‑day lives, including the way we interact and conduct business. In the midst of this, WSU has had to change the way learning and teaching occurs. Traditional face‑to‑face tuition had to be adapted by moving to the online mode of teaching and learning to both minimise the time lost in the academic project and protect staff and students from the devastating effects of the virus. This article reflects the actions taken by the University and describes its pilot‑project approach to online learning and those processes it has put in place to ensure its effective implementation. While it is accepted that switching to an online mode of teaching and learning can facilitate flexibility in space and time, the reality is that the majority of students at WSU – mainly due to their geographical and socio‑economic environments – experience daily challenges ranging from poor network coverage, lack of internet connectivity, lack of electricity and other socio‑economic impediments that make online learning stressful or beyond their reach. In this article, we present a model that could be used by higher education institutions (HEIs) to respond to Covid‑19 in the short term. The proposed model is underpinned by a framework that caters for students who are readily able to access online learning, students with intermittent access to online facilities and finally, students who cannot access online education. First, we provide a brief description of online learning, highlighting the challenges presented to teaching and learning by this approach. We argue that our context and education policies present additional problems that militate against the adoption of online strategies by most HEIs. In the final instance, we present a framework that is better suited to our context and can be used during and after the lockdown. Data were collected using online questionnaires with both structured and open‑ended questions from both lecturers and students to determine their experiences with the testing project. Lastly, we draw conclusions based on the findings of the study.
- Full Text:
- Date Issued: 2021
Modulation of the optical properties of chiral porphyrin dimers by introducing bridged chiral amide-bonds
- Qin, Mingfeng, Zhang, Zhen, Zhu, Weihua, Mack, John, Soy, Rodah C, Nyokong, Tebello, Liang, Xu
- Authors: Qin, Mingfeng , Zhang, Zhen , Zhu, Weihua , Mack, John , Soy, Rodah C , Nyokong, Tebello , Liang, Xu
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190815 , vital:45031 , xlink:href="https://doi.org/10.1142/S1088424620500492"
- Description: The d/l-enantiomers of a series of three Zn(II)tetraarylporphyrin dimers were synthesized and isolated by incorporating a bridging amide-bonded xanthene moiety at the para-position of one of the meso-aryl rings. The electronic structures and optical properties were modulated by incorporating chiral amino acid moieties into the amide-bonding moieties of the xanthene bridge that contain methyl, tolyl and 2-methylindole substituents. A cofacial dimer was formed in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) resulting in a significant red shift of the B band, due to a relative destabilization of the HOMO, which has large MO coefficients on the pyrrole nitrogens. The sign sequences observed in the B band region of the CD spectra due to the presence of the chiral amino acid moieties were modified due to this change in geometry. Significant CD intensity is also observed in the B band region of the CD spectra of anion radical species during in situ spectroelectrochemical measurements.
- Full Text:
- Date Issued: 2021
- Authors: Qin, Mingfeng , Zhang, Zhen , Zhu, Weihua , Mack, John , Soy, Rodah C , Nyokong, Tebello , Liang, Xu
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190815 , vital:45031 , xlink:href="https://doi.org/10.1142/S1088424620500492"
- Description: The d/l-enantiomers of a series of three Zn(II)tetraarylporphyrin dimers were synthesized and isolated by incorporating a bridging amide-bonded xanthene moiety at the para-position of one of the meso-aryl rings. The electronic structures and optical properties were modulated by incorporating chiral amino acid moieties into the amide-bonding moieties of the xanthene bridge that contain methyl, tolyl and 2-methylindole substituents. A cofacial dimer was formed in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) resulting in a significant red shift of the B band, due to a relative destabilization of the HOMO, which has large MO coefficients on the pyrrole nitrogens. The sign sequences observed in the B band region of the CD spectra due to the presence of the chiral amino acid moieties were modified due to this change in geometry. Significant CD intensity is also observed in the B band region of the CD spectra of anion radical species during in situ spectroelectrochemical measurements.
- Full Text:
- Date Issued: 2021
Monitoring and Management Mechanisms on Stress in HEI in Eastern Cape Province in South Africa: Critical Review
- Asoba, Samson Nambei, Patricia, Nteboheng Mefi
- Authors: Asoba, Samson Nambei , Patricia, Nteboheng Mefi
- Date: 2021
- Subjects: Teachers--Job stress , Ill-Discipline of Learners , Middle school education -- Parent participation
- Language: English
- Type: text , article , Article
- Identifier: http://hdl.handle.net/11260/8068 , vital:61393 , xlink:href="https://www.abacademies.org/articles/monitoring-and-management-mechanisms-on-stress-in-hei-in-eastern-cape-province-in-south-africa-critical-review-10636.html"
- Description: Stress is a global phenomenon that affects everyone regardless of gender, resources and environment. Although this phenomenon is well researched, teachers’ experiences of stress remains a worrying challenge particularly to schools’ effectiveness. This study sought to establish how monitoring and management mechanism that can assist teachers to cope with stress challenges. These are some of the recommendation: that the school disciplinary committee should be trained in various disciplinary measures that may be implemented in the school to curb learner ill-discipline and lack of commitment, that working relationship should be built between schools and the Department of Basic Education, motivational speakers and educational counsellors should meet with all learners on a regular basis to motivate them to have high desire for and interest in education and to build their self-confidence in the classroom, providing all the schools with healthy environment in classrooms, provision of learning and teaching materials to all schools, schools should set up an effective school-parents partnership in order to promote a safe drug and alcohol free environment, employ enough teachers in all secondary schools and the Department of Basic Education at district level should make room for stress management workshops for teachers.
- Full Text:
- Date Issued: 2021
- Authors: Asoba, Samson Nambei , Patricia, Nteboheng Mefi
- Date: 2021
- Subjects: Teachers--Job stress , Ill-Discipline of Learners , Middle school education -- Parent participation
- Language: English
- Type: text , article , Article
- Identifier: http://hdl.handle.net/11260/8068 , vital:61393 , xlink:href="https://www.abacademies.org/articles/monitoring-and-management-mechanisms-on-stress-in-hei-in-eastern-cape-province-in-south-africa-critical-review-10636.html"
- Description: Stress is a global phenomenon that affects everyone regardless of gender, resources and environment. Although this phenomenon is well researched, teachers’ experiences of stress remains a worrying challenge particularly to schools’ effectiveness. This study sought to establish how monitoring and management mechanism that can assist teachers to cope with stress challenges. These are some of the recommendation: that the school disciplinary committee should be trained in various disciplinary measures that may be implemented in the school to curb learner ill-discipline and lack of commitment, that working relationship should be built between schools and the Department of Basic Education, motivational speakers and educational counsellors should meet with all learners on a regular basis to motivate them to have high desire for and interest in education and to build their self-confidence in the classroom, providing all the schools with healthy environment in classrooms, provision of learning and teaching materials to all schools, schools should set up an effective school-parents partnership in order to promote a safe drug and alcohol free environment, employ enough teachers in all secondary schools and the Department of Basic Education at district level should make room for stress management workshops for teachers.
- Full Text:
- Date Issued: 2021
Muco-adhesive clarithromycin-loaded nanostructured lipid carriers for ocular delivery: Formulation, characterization, cytotoxicity and stability
- Makoni, Pedzisai A, Khamanga, Sandile M, Walker, Roderick B
- Authors: Makoni, Pedzisai A , Khamanga, Sandile M , Walker, Roderick B
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183150 , vital:43916 , xlink:href="https://doi.org/10.1016/j.jddst.2020.102171"
- Description: Topical ophthalmic formulations are the preferred approach to treat the anterior segment of the eye as it is a non-invasive therapeutic approach. The ocular bioavailability of drugs is generally limited, due to the presence of impervious anatomical barriers and low residence time and contact with the target tissue. Optimization of clarithromycin-loaded nanostructured lipid carriers using Design of Experiments was undertaken. Manufacture of nanostructured lipid carriers was achieved using hot emulsification ultrasonication. Formulation and process parameters were successfully identified following screening and subsequently optimized using Tween® 20, as a stabilizer. Muco-adhesive properties that could potentially increase ocular residence time, in vitro clarithromycin release and cytotoxicity against HeLa cells were evaluated. Short term stability studies of the optimized lipidic formulations was assessed at 4 °C and 22 °C. The optimized formulation exhibited muco-adhesive properties under stationary conditions assessed using Laser Doppler Anemometry, sustained release of API over 24 h under in vitro conditions. In vitro cytotoxicity studies revealed that the NLC were less cytotoxic to HeLa cells in comparison to pure API. The results suggest that the optimized carriers may have the potential to enhance precorneal retention, increase ocular availability and permit dose reduction or permit use of a longer dosing frequency.
- Full Text:
- Date Issued: 2021
- Authors: Makoni, Pedzisai A , Khamanga, Sandile M , Walker, Roderick B
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183150 , vital:43916 , xlink:href="https://doi.org/10.1016/j.jddst.2020.102171"
- Description: Topical ophthalmic formulations are the preferred approach to treat the anterior segment of the eye as it is a non-invasive therapeutic approach. The ocular bioavailability of drugs is generally limited, due to the presence of impervious anatomical barriers and low residence time and contact with the target tissue. Optimization of clarithromycin-loaded nanostructured lipid carriers using Design of Experiments was undertaken. Manufacture of nanostructured lipid carriers was achieved using hot emulsification ultrasonication. Formulation and process parameters were successfully identified following screening and subsequently optimized using Tween® 20, as a stabilizer. Muco-adhesive properties that could potentially increase ocular residence time, in vitro clarithromycin release and cytotoxicity against HeLa cells were evaluated. Short term stability studies of the optimized lipidic formulations was assessed at 4 °C and 22 °C. The optimized formulation exhibited muco-adhesive properties under stationary conditions assessed using Laser Doppler Anemometry, sustained release of API over 24 h under in vitro conditions. In vitro cytotoxicity studies revealed that the NLC were less cytotoxic to HeLa cells in comparison to pure API. The results suggest that the optimized carriers may have the potential to enhance precorneal retention, increase ocular availability and permit dose reduction or permit use of a longer dosing frequency.
- Full Text:
- Date Issued: 2021
Naked Eye and Colorimetric Detection of Cyanide with a 1, 3‐Diethyl‐2‐thiobarbituric Acid Substituted Ferrocene Chemosensor
- Babu, Balaji, Mack, John, Nyokong, Tebello
- Authors: Babu, Balaji , Mack, John , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190567 , vital:45006 , xlink:href="https://doi.org/10.1002/slct.202100163"
- Description: A 1,3-diethyl-2-thiobarbituric-acid-substituted ferrocene (FET) has been evaluated for its cyanide sensing ability by UV-visible absorption spectroscopy and other characterization methods. FET provides a ratiometric colorimetric chemosensor for the CN− anion detection in 1 : 1 DMSO/H2O (v/v) solution. The addition of CN− results in an immediate color change from dark blue to pale orange that is visible to the naked eye. Mechanism studies and molecular modelling with TD-DFT calculations demonstrate that nucleophilic addition of CN− to an electrophilic sp2-hybridized carbon atom blocks charge transfer from the ferrocene ring complex to the thiobarbituric acid moiety. The FET sensor exhibits excellent selectivity for CN− and a limit of detection of 0.2 μM.
- Full Text:
- Date Issued: 2021
- Authors: Babu, Balaji , Mack, John , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190567 , vital:45006 , xlink:href="https://doi.org/10.1002/slct.202100163"
- Description: A 1,3-diethyl-2-thiobarbituric-acid-substituted ferrocene (FET) has been evaluated for its cyanide sensing ability by UV-visible absorption spectroscopy and other characterization methods. FET provides a ratiometric colorimetric chemosensor for the CN− anion detection in 1 : 1 DMSO/H2O (v/v) solution. The addition of CN− results in an immediate color change from dark blue to pale orange that is visible to the naked eye. Mechanism studies and molecular modelling with TD-DFT calculations demonstrate that nucleophilic addition of CN− to an electrophilic sp2-hybridized carbon atom blocks charge transfer from the ferrocene ring complex to the thiobarbituric acid moiety. The FET sensor exhibits excellent selectivity for CN− and a limit of detection of 0.2 μM.
- Full Text:
- Date Issued: 2021
Nano Co-Crystal Embedded Stimuli-Responsive Hydrogels: A Potential Approach to Treat HIV/AIDS
- Witika, Bwalya A, Stander, Jessé-Clint, Smith, Vincent J, Walker, Roderick B
- Authors: Witika, Bwalya A , Stander, Jessé-Clint , Smith, Vincent J , Walker, Roderick B
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183137 , vital:43915 , xlink:href="https://doi.org/10.3390/pharmaceutics13020127"
- Description: Currently, the human immunodeficiency virus (HIV) that causes acquired immunodeficiency syndrome (AIDS) can only be treated successfully, using combination antiretroviral (ARV) therapy. Lamivudine (3TC) and zidovudine (AZT), two compounds used for the treatment of HIV and prevention of disease progression to AIDS are used in such combinations. Successful therapy with 3TC and AZT requires frequent dosing that may lead to reduced adherence, resistance and consequently treatment failure. Improved toxicity profiles of 3TC and AZT were observed when combined as a nano co-crystal (NCC). The use of stimuli-responsive delivery systems provides an opportunity to overcome the challenge of frequent dosing, by controlling and/or sustaining delivery of drugs. Preliminary studies undertaken to identify a suitable composition for a stimulus-responsive in situ forming hydrogel carrier for 3TC-AZT NCC were conducted, and the gelation and erosion time were determined. A 25% w/w Pluronic® F-127 thermoresponsive hydrogel was identified as a suitable carrier as it exhibited a gelation time of 5 min and an erosion time of 7 days. NCC-loaded hydrogels were evaluated using in vitro dissolution and cytotoxicity assays. In vitro dissolution undertaken using membrane-less diffusion over 168 h revealed that 3TC and AZT release from NCC-loaded hydrogels was complete and followed zero-order kinetic processes, whereas those loaded with the micro co-crystal and physical mixture were incomplete and best described using the Korsmeyer–Peppas kinetic model. The release of AZT and 3TC from the physical mixture and MCC-loaded gel exhibited a value for n of 0.595 for AZT release from the physical mixture and 0.540 for the MCC technology, whereas the release exponent for 3TC was 0.513 for the physical mixture and 0.557 for the MCC technology indicating that diffusion and erosion controlled 3TC and AZT release. In vitro cytotoxicity assay data revealed that the addition of NCC to the thermoresponsive hydrogel resulted in an improved cell viability of 88.0% ± 5.0% when compared to the cell viability of the NCC of 76.9% ± 5.0%. The results suggest that the use of a thermoresponsive nanosuspension may have the potential to be delivered as an intramuscular injection that can subsequently increase bioavailability and permit dose reduction and/or permit use of a longer dosing frequency.
- Full Text:
- Date Issued: 2021
- Authors: Witika, Bwalya A , Stander, Jessé-Clint , Smith, Vincent J , Walker, Roderick B
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183137 , vital:43915 , xlink:href="https://doi.org/10.3390/pharmaceutics13020127"
- Description: Currently, the human immunodeficiency virus (HIV) that causes acquired immunodeficiency syndrome (AIDS) can only be treated successfully, using combination antiretroviral (ARV) therapy. Lamivudine (3TC) and zidovudine (AZT), two compounds used for the treatment of HIV and prevention of disease progression to AIDS are used in such combinations. Successful therapy with 3TC and AZT requires frequent dosing that may lead to reduced adherence, resistance and consequently treatment failure. Improved toxicity profiles of 3TC and AZT were observed when combined as a nano co-crystal (NCC). The use of stimuli-responsive delivery systems provides an opportunity to overcome the challenge of frequent dosing, by controlling and/or sustaining delivery of drugs. Preliminary studies undertaken to identify a suitable composition for a stimulus-responsive in situ forming hydrogel carrier for 3TC-AZT NCC were conducted, and the gelation and erosion time were determined. A 25% w/w Pluronic® F-127 thermoresponsive hydrogel was identified as a suitable carrier as it exhibited a gelation time of 5 min and an erosion time of 7 days. NCC-loaded hydrogels were evaluated using in vitro dissolution and cytotoxicity assays. In vitro dissolution undertaken using membrane-less diffusion over 168 h revealed that 3TC and AZT release from NCC-loaded hydrogels was complete and followed zero-order kinetic processes, whereas those loaded with the micro co-crystal and physical mixture were incomplete and best described using the Korsmeyer–Peppas kinetic model. The release of AZT and 3TC from the physical mixture and MCC-loaded gel exhibited a value for n of 0.595 for AZT release from the physical mixture and 0.540 for the MCC technology, whereas the release exponent for 3TC was 0.513 for the physical mixture and 0.557 for the MCC technology indicating that diffusion and erosion controlled 3TC and AZT release. In vitro cytotoxicity assay data revealed that the addition of NCC to the thermoresponsive hydrogel resulted in an improved cell viability of 88.0% ± 5.0% when compared to the cell viability of the NCC of 76.9% ± 5.0%. The results suggest that the use of a thermoresponsive nanosuspension may have the potential to be delivered as an intramuscular injection that can subsequently increase bioavailability and permit dose reduction and/or permit use of a longer dosing frequency.
- Full Text:
- Date Issued: 2021
Nanohybrid electrocatalyst based on cobalt phthalocyanine-carbon nanotube-reduced graphene oxide for ultrasensitive detection of glucose in human saliva
- Adeniyi, Omotayo, Nwahara, Nnamdi, Mwanza, Daniel, Nyokong, Tebello, Mashazi, Philani N
- Authors: Adeniyi, Omotayo , Nwahara, Nnamdi , Mwanza, Daniel , Nyokong, Tebello , Mashazi, Philani N
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/231356 , vital:49880 , xlink:href="https://doi.org/10.1016/j.snb.2021.130723"
- Description: The current diabetes management systems require collecting blood samples via an invasive and painful finger pricking leading to the formation of callus, scarring and loss of sensibility to patients due to continuous monitoring. Therefore, a non-invasive and painless method of determining glucose levels would be desirable to diabetes patients who need constant monitoring. Saliva glucose measurement is a non-invasive alternative for diabetes management. A highly sensitive, stable, and selective non-enzymatic electrochemical sensor that can accurately quantify saliva glucose is required. A single-walled carbon nanotube/reduced graphene oxide/cobalt phthalocyanines nanohybrid modified glassy carbon electrode (GCE-SWCNT/rGO/CoPc) has been fabricated for the non-enzymatic determination of glucose in human saliva. The SWCNT/rGO/CoPc was characterized using various spectroscopic, microscopic, and electrochemical techniques. The synergistic effect between SWCNT, rGO, and CoPc facilitated excellent electron transfer process that improved the sensor sensitivity. The GCE-SWCNT/rGO/CoPc sensor exhibited two linear responses in the 0.30 μM to 0.50 mM and 0.50–5.0 mM glucose concentration ranges, and the detection limit was 0.12 μM. The sensor had an excellent saliva glucose detection sensitivity of 992.4 μA·mM−1·cm−2 and high specificity for glucose in the presence of other coexisting analytes. In addition, it showed good storage stability, reusability, and a fast response time of about 1.2 s. The GCE-SWCNT/rGO/CoPc nanohybrid electrode showed excellent potential for developing accurate, non-invasive, and painless glucose sensing.
- Full Text:
- Date Issued: 2021
- Authors: Adeniyi, Omotayo , Nwahara, Nnamdi , Mwanza, Daniel , Nyokong, Tebello , Mashazi, Philani N
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/231356 , vital:49880 , xlink:href="https://doi.org/10.1016/j.snb.2021.130723"
- Description: The current diabetes management systems require collecting blood samples via an invasive and painful finger pricking leading to the formation of callus, scarring and loss of sensibility to patients due to continuous monitoring. Therefore, a non-invasive and painless method of determining glucose levels would be desirable to diabetes patients who need constant monitoring. Saliva glucose measurement is a non-invasive alternative for diabetes management. A highly sensitive, stable, and selective non-enzymatic electrochemical sensor that can accurately quantify saliva glucose is required. A single-walled carbon nanotube/reduced graphene oxide/cobalt phthalocyanines nanohybrid modified glassy carbon electrode (GCE-SWCNT/rGO/CoPc) has been fabricated for the non-enzymatic determination of glucose in human saliva. The SWCNT/rGO/CoPc was characterized using various spectroscopic, microscopic, and electrochemical techniques. The synergistic effect between SWCNT, rGO, and CoPc facilitated excellent electron transfer process that improved the sensor sensitivity. The GCE-SWCNT/rGO/CoPc sensor exhibited two linear responses in the 0.30 μM to 0.50 mM and 0.50–5.0 mM glucose concentration ranges, and the detection limit was 0.12 μM. The sensor had an excellent saliva glucose detection sensitivity of 992.4 μA·mM−1·cm−2 and high specificity for glucose in the presence of other coexisting analytes. In addition, it showed good storage stability, reusability, and a fast response time of about 1.2 s. The GCE-SWCNT/rGO/CoPc nanohybrid electrode showed excellent potential for developing accurate, non-invasive, and painless glucose sensing.
- Full Text:
- Date Issued: 2021
Nationwide Assessment of Population Structure, Stability and Plant Morphology of Two Mimusops Species along a Social-Ecological Gradient in Benin, West Africa
- Sinasson, Gisèle K, Shackleton, Charlie M, Sinsin, Brice
- Authors: Sinasson, Gisèle K , Shackleton, Charlie M , Sinsin, Brice
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/399805 , vital:69560 , xlink:href="https://doi.org/10.3390/f12111575"
- Description: Understanding tree species autecology and population structure supports effective conservation actions. Of particular importance are multipurpose trees that provide non-timber forest products (NTFPs). We assessed the population structures and morphologies of two species of NTFP trees in the genus Mimusops across bioclimatic zones in Benin by sampling 288 plots within 11 forests. Structural characteristics were compared between species, forests and zones. Correlations were also observed between Mimusops tree regeneration density, tree features and ecological characteristics. The density of trees ≥5 cm and of regeneration and mean tree height were higher for M. andongensis (within more protected forest) than M. kummel (in forests with access to people), while the highest mean diameter was observed for M. kummel. Tree and regeneration densities and mean height were greatest in the humid zone of Benin, whilst the largest mean diameter was obtained in the sub-humid zone. The results showed significant correlations between regeneration density and soil properties for M. andongensis but not for M. kummel. The correlations between tree morphology and soil characteristics were weak for both species. Ecological characteristics, along with the species’ functional traits and pressures, are important factors related to the observed differences between the species. All diameter classes were represented, and the population seemed more stable in the more protected forest relative to other forests. Mimusops trees with a diameter of 5–15 cm represented more than 30% of this species in most forests; this suggests, for M. kummel, whose trees flower when quite small (≥6 cm dbh), that there are sufficient reproductive trees. Thus, as a long-lived species, its populations could be maintained even with low/episodic recruitment. However, we found no regeneration in many forests and climate change could threaten populations. Therefore, it is important to investigate regeneration growth and dynamics, seed production and germination of the species in relation to the biophysical conditions and disturbances experienced by Mimusops stands.
- Full Text:
- Date Issued: 2021
- Authors: Sinasson, Gisèle K , Shackleton, Charlie M , Sinsin, Brice
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/399805 , vital:69560 , xlink:href="https://doi.org/10.3390/f12111575"
- Description: Understanding tree species autecology and population structure supports effective conservation actions. Of particular importance are multipurpose trees that provide non-timber forest products (NTFPs). We assessed the population structures and morphologies of two species of NTFP trees in the genus Mimusops across bioclimatic zones in Benin by sampling 288 plots within 11 forests. Structural characteristics were compared between species, forests and zones. Correlations were also observed between Mimusops tree regeneration density, tree features and ecological characteristics. The density of trees ≥5 cm and of regeneration and mean tree height were higher for M. andongensis (within more protected forest) than M. kummel (in forests with access to people), while the highest mean diameter was observed for M. kummel. Tree and regeneration densities and mean height were greatest in the humid zone of Benin, whilst the largest mean diameter was obtained in the sub-humid zone. The results showed significant correlations between regeneration density and soil properties for M. andongensis but not for M. kummel. The correlations between tree morphology and soil characteristics were weak for both species. Ecological characteristics, along with the species’ functional traits and pressures, are important factors related to the observed differences between the species. All diameter classes were represented, and the population seemed more stable in the more protected forest relative to other forests. Mimusops trees with a diameter of 5–15 cm represented more than 30% of this species in most forests; this suggests, for M. kummel, whose trees flower when quite small (≥6 cm dbh), that there are sufficient reproductive trees. Thus, as a long-lived species, its populations could be maintained even with low/episodic recruitment. However, we found no regeneration in many forests and climate change could threaten populations. Therefore, it is important to investigate regeneration growth and dynamics, seed production and germination of the species in relation to the biophysical conditions and disturbances experienced by Mimusops stands.
- Full Text:
- Date Issued: 2021