But is it publishable? Mastering the MMed message
- Authors: A G Parrish , E S Grossman,
- Date: 202
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3353 , vital:43318 , http://www.samj.org.za/index.php/samj/article/view/13033
- Description: The research requirement for South African specialist registration offers opportunities and challenges. For some clinicians it may spark a lifelong interest in clinical investigation, while for many others it may provide a potential publication opportunity. Integrating the specific requirements of an MMed mini-dissertation with those of standard medical publications can be difficult for first-time authors and their supervisors; published guidance caters to full-length laboratory Master’s or doctoral research. We suggest that research is more likely to be publishable if it is locally relevant, has a clear clinical message and is coherently presented.
- Full Text:
- Date Issued: 202
- Authors: A G Parrish , E S Grossman,
- Date: 202
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3353 , vital:43318 , http://www.samj.org.za/index.php/samj/article/view/13033
- Description: The research requirement for South African specialist registration offers opportunities and challenges. For some clinicians it may spark a lifelong interest in clinical investigation, while for many others it may provide a potential publication opportunity. Integrating the specific requirements of an MMed mini-dissertation with those of standard medical publications can be difficult for first-time authors and their supervisors; published guidance caters to full-length laboratory Master’s or doctoral research. We suggest that research is more likely to be publishable if it is locally relevant, has a clear clinical message and is coherently presented.
- Full Text:
- Date Issued: 202
Essential medicine selection during the COVID-19 pandemic: Enabling access in uncharted territory
- Authors: A G Parrish
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3364 , vital:43319 , http://www.samj.org.za/index.php/samj/article/view/13086
- Description: The COVID-19 pandemic requires urgent decisions regarding treatment policy in the face of rapidly evolving evidence. In response, the South African Essential Medicines List Committee established a subcommittee to systematically review and appraise emerging evidence, within very short timelines, in order to inform the National Department of Health COVID-19 treatment guidelines. To date, the subcommittee has reviewed 14 potential treatments, and made recommendations based on local context, feasibility, resource requirements and equity. Here we describe the rapid review and evidence-to-decision process, using remdesivir and dexamethasone as examples. Our experience is that conducting rapid reviews is a practical and efficient way to address medicine policy questions under pandemic conditions.
- Full Text:
- Date Issued: 2020
- Authors: A G Parrish
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3364 , vital:43319 , http://www.samj.org.za/index.php/samj/article/view/13086
- Description: The COVID-19 pandemic requires urgent decisions regarding treatment policy in the face of rapidly evolving evidence. In response, the South African Essential Medicines List Committee established a subcommittee to systematically review and appraise emerging evidence, within very short timelines, in order to inform the National Department of Health COVID-19 treatment guidelines. To date, the subcommittee has reviewed 14 potential treatments, and made recommendations based on local context, feasibility, resource requirements and equity. Here we describe the rapid review and evidence-to-decision process, using remdesivir and dexamethasone as examples. Our experience is that conducting rapid reviews is a practical and efficient way to address medicine policy questions under pandemic conditions.
- Full Text:
- Date Issued: 2020
Effects of an eight-week lumbar stabilization exercise programme on selected variables of patients with chronic low back pain:
- Abass, Ademola O, Alli, Abiola R, Olagbegi, Oladapo M, Christie, Candice J, Bolarinde, Olufemi S
- Authors: Abass, Ademola O , Alli, Abiola R , Olagbegi, Oladapo M , Christie, Candice J , Bolarinde, Olufemi S
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150307 , vital:38966 , DOI: https://doi.org/10.3329/bjms.v19i3.45864
- Description: Lumbar stabilisation exercise has been shown to reduce pain and disability in patients with low back pain but information on its potential benefits in term of back muscle endurance is scarce. This study was aimed at investigating the effects of augmenting conventional physiotherapy with lumbar stabilization exercises on selected variables of patients with non-specific chronic low back pain (NSCLBP).
- Full Text:
- Date Issued: 2020
- Authors: Abass, Ademola O , Alli, Abiola R , Olagbegi, Oladapo M , Christie, Candice J , Bolarinde, Olufemi S
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150307 , vital:38966 , DOI: https://doi.org/10.3329/bjms.v19i3.45864
- Description: Lumbar stabilisation exercise has been shown to reduce pain and disability in patients with low back pain but information on its potential benefits in term of back muscle endurance is scarce. This study was aimed at investigating the effects of augmenting conventional physiotherapy with lumbar stabilization exercises on selected variables of patients with non-specific chronic low back pain (NSCLBP).
- Full Text:
- Date Issued: 2020
Genetic and biological characterisation of a novel Plutella xylostella granulovirus, PlxyGV-SA
- Abdulkadir, Fatima, Knox, Caroline M, Marsberg, Tamryn, Hill, Martin P, Moore, Sean D
- Authors: Abdulkadir, Fatima , Knox, Caroline M , Marsberg, Tamryn , Hill, Martin P , Moore, Sean D
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417971 , vital:71498 , xlink:href="https://doi.org/10.1007/s10526-015-9666-3"
- Description: Plutella xylostella granulovirus (PlxyGV) has been isolated from insect populations in many countries and is considered a potential biopesticide for sustainable control of P. xylostella (L.) (Lepidoptera: Plutellidae). Several PlxyGV isolates have been genetically characterised, and the full genome sequence of PlxyGV-Japan is available for comparison with novel isolates. A South African PlxyGV was recently recovered from an overcrowded laboratory P. xylostella colony and identified as a genetically distinct isolate by sequencing of the granulin gene and restriction endonuclease (REN) analysis of genomic DNA. In this report, PlxyGV-SA was further characterised by PCR amplification and sequencing of egt, lef-8 and lef-9 genes, and several amino acid substitutions were observed. The PstI REN profile of PlxyGV-SA was different from that of PlxyGV-Japan in terms of band size and number, thereby confirming its novel genetic identity. Surface dose bioassays showed that PlxyGV-SA is pathogenic to neonate but not late instar larvae at the same and higher virus doses, indicating that a biopesticide should be targeted at early larval stages in the field.
- Full Text:
- Date Issued: 2015
- Authors: Abdulkadir, Fatima , Knox, Caroline M , Marsberg, Tamryn , Hill, Martin P , Moore, Sean D
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417971 , vital:71498 , xlink:href="https://doi.org/10.1007/s10526-015-9666-3"
- Description: Plutella xylostella granulovirus (PlxyGV) has been isolated from insect populations in many countries and is considered a potential biopesticide for sustainable control of P. xylostella (L.) (Lepidoptera: Plutellidae). Several PlxyGV isolates have been genetically characterised, and the full genome sequence of PlxyGV-Japan is available for comparison with novel isolates. A South African PlxyGV was recently recovered from an overcrowded laboratory P. xylostella colony and identified as a genetically distinct isolate by sequencing of the granulin gene and restriction endonuclease (REN) analysis of genomic DNA. In this report, PlxyGV-SA was further characterised by PCR amplification and sequencing of egt, lef-8 and lef-9 genes, and several amino acid substitutions were observed. The PstI REN profile of PlxyGV-SA was different from that of PlxyGV-Japan in terms of band size and number, thereby confirming its novel genetic identity. Surface dose bioassays showed that PlxyGV-SA is pathogenic to neonate but not late instar larvae at the same and higher virus doses, indicating that a biopesticide should be targeted at early larval stages in the field.
- Full Text:
- Date Issued: 2015
Morphological and genetic characterization of a South African Plutella xylostella granulovirus (plxy GV) isolate
- Abdulkadir, Fatima, Marsberg, Tamryn, Knox, Caroline M, Hill, Martin P, Moore, Sean D
- Authors: Abdulkadir, Fatima , Marsberg, Tamryn , Knox, Caroline M , Hill, Martin P , Moore, Sean D
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/406117 , vital:70240 , xlink:href="https://hdl.handle.net/10520/EJC132828"
- Description: Plutella xylostella (L.) (Lepidoptera: Plutellidae), also known as diamondback moth, is a destructive insect pest of cruciferous crops (Talekar and Shelton 1993; Shelton 2004). The pest occurs wherever its host plants are cultivated and the global annual cost of damage and control is estimated to be US$4-5 billion (Zalucki et al. 2012). The extensive use of synthetic pesticides for control combined with the high fecundity of P. xylostella has resulted in the pest developing resistance to nearly all classes of insecticides (Grzywacz et al. 2009). Moreover, these chemicals have negative environmental implications and may affect non-target species, some of which are natural enemies of the pest.
- Full Text:
- Date Issued: 2013
- Authors: Abdulkadir, Fatima , Marsberg, Tamryn , Knox, Caroline M , Hill, Martin P , Moore, Sean D
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/406117 , vital:70240 , xlink:href="https://hdl.handle.net/10520/EJC132828"
- Description: Plutella xylostella (L.) (Lepidoptera: Plutellidae), also known as diamondback moth, is a destructive insect pest of cruciferous crops (Talekar and Shelton 1993; Shelton 2004). The pest occurs wherever its host plants are cultivated and the global annual cost of damage and control is estimated to be US$4-5 billion (Zalucki et al. 2012). The extensive use of synthetic pesticides for control combined with the high fecundity of P. xylostella has resulted in the pest developing resistance to nearly all classes of insecticides (Grzywacz et al. 2009). Moreover, these chemicals have negative environmental implications and may affect non-target species, some of which are natural enemies of the pest.
- Full Text:
- Date Issued: 2013
Pyridone substituted phthalocyanines: Photophysico-chemical properties and TD-DFT calculations
- Abdurrahmanoğlu, Şaziye, Canlica, Mevlüde, Mack, John, Nyokong, Tebello
- Authors: Abdurrahmanoğlu, Şaziye , Canlica, Mevlüde , Mack, John , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188216 , vital:44735 , xlink:href="https://doi.org/10.1142/S1088424617500730"
- Description: 4-(6-methyl-3-nitro-2-oxo-1,2-dihydropyridin-4-yloxy)phthalonitrile has been used to prepare a novel Zn(II) phthalocyanines with four peripheral pyridone substituents. The compound has been characterized by UV-visible absorption, FT-IR and 11H-NMR spectroscopy, elemental analysis and MALDI-TOF mass spectroscopy. The fluorescence, triplet quantum and singlet oxygen quantum yields have been determined and TD-DFT calculations have been used to identify trends in the electronic structure.
- Full Text:
- Date Issued: 2018
- Authors: Abdurrahmanoğlu, Şaziye , Canlica, Mevlüde , Mack, John , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188216 , vital:44735 , xlink:href="https://doi.org/10.1142/S1088424617500730"
- Description: 4-(6-methyl-3-nitro-2-oxo-1,2-dihydropyridin-4-yloxy)phthalonitrile has been used to prepare a novel Zn(II) phthalocyanines with four peripheral pyridone substituents. The compound has been characterized by UV-visible absorption, FT-IR and 11H-NMR spectroscopy, elemental analysis and MALDI-TOF mass spectroscopy. The fluorescence, triplet quantum and singlet oxygen quantum yields have been determined and TD-DFT calculations have been used to identify trends in the electronic structure.
- Full Text:
- Date Issued: 2018
Conjuring our beings: Stacey Gillian Abe and Immy Mali in conversational partnership
- Abe, Stacey Gillian, Mali, Immy
- Authors: Abe, Stacey Gillian , Mali, Immy
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145963 , vital:38482 , https://0-doi.org.wam.seals.ac.za/10.1162/afar_a_00457
- Description: The series of Conversational Partnerships began in 2017 in African Arts vol. 50, no. 2, with a conversation between two artists: Eria Nsubuga SANE from Uganda and Sikhumbuzo Makandula from South Africa. The format of a “conversational partnership” (Rubin and Rubin 2012: 7) emphasizes the cocreation of meaning by the interviewer and interviewee as coauthors. This enables a move away from the art history format of the interviewer (usually a writer) assuming the role of the sole author and the interviewee (often an artist) having no status as an author despite the fact that her or his practice-led creation of knowledge is foundational to the content of the interview. Stacey Gillian Abe and Immy Mali participated in a joint artists' residency as part of the RAW program at Rhodes University in South Africa from November to December 2017. During this time, they engaged with each other's practice-led work, and they created this conversational partnership at a writing breakaway in the Eastern Cape.
- Full Text:
- Date Issued: 2019
- Authors: Abe, Stacey Gillian , Mali, Immy
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145963 , vital:38482 , https://0-doi.org.wam.seals.ac.za/10.1162/afar_a_00457
- Description: The series of Conversational Partnerships began in 2017 in African Arts vol. 50, no. 2, with a conversation between two artists: Eria Nsubuga SANE from Uganda and Sikhumbuzo Makandula from South Africa. The format of a “conversational partnership” (Rubin and Rubin 2012: 7) emphasizes the cocreation of meaning by the interviewer and interviewee as coauthors. This enables a move away from the art history format of the interviewer (usually a writer) assuming the role of the sole author and the interviewee (often an artist) having no status as an author despite the fact that her or his practice-led creation of knowledge is foundational to the content of the interview. Stacey Gillian Abe and Immy Mali participated in a joint artists' residency as part of the RAW program at Rhodes University in South Africa from November to December 2017. During this time, they engaged with each other's practice-led work, and they created this conversational partnership at a writing breakaway in the Eastern Cape.
- Full Text:
- Date Issued: 2019
Rural Tourism and Inclusive Development in Port St. Johns - South Africa
- Acha-Anyi, Paul Nkemngu, Ndolose, Ludwe, Solomon, Khunou Pula
- Authors: Acha-Anyi, Paul Nkemngu , Ndolose, Ludwe , Solomon, Khunou Pula
- Date: 2021
- Subjects: Rural tourism Community Inclusive development; Sustainable development Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7023 , vital:52758 , xlink:href=":https://doi.org/10.46222/ajhtl.19770720.197"
- Description: The purpose of this study was to explore ways of achieving an inclusive approach to tourism development in rural communities. Although tourism has generally been recommended as a means of orchestrating development in rural communities, achieving this laudable goal has often been illusive due to the fragmented approach adopted by tourism stakeholders. An exploratory quantitative research approach was adopted by using a structured survey instrument to generate 307 valid responses from community members in Port St. John in the Eastern Cape Province (ECP) of South Africa. Results obtained reveal similarities and some differences based on demographic characteristics with regards to the benefits of rural tourism to the community. Importantly, the study illuminates the fragmented way in which residents perceive tourism benefits, both from a gender perspective and personal benefit versus community dichotomy. The paper discusses policy as well as practical local economic development implications. Keywords: Rural tourism; community; Port St. Johns; inclusive development; sustainable development
- Full Text:
- Date Issued: 2021
- Authors: Acha-Anyi, Paul Nkemngu , Ndolose, Ludwe , Solomon, Khunou Pula
- Date: 2021
- Subjects: Rural tourism Community Inclusive development; Sustainable development Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7023 , vital:52758 , xlink:href=":https://doi.org/10.46222/ajhtl.19770720.197"
- Description: The purpose of this study was to explore ways of achieving an inclusive approach to tourism development in rural communities. Although tourism has generally been recommended as a means of orchestrating development in rural communities, achieving this laudable goal has often been illusive due to the fragmented approach adopted by tourism stakeholders. An exploratory quantitative research approach was adopted by using a structured survey instrument to generate 307 valid responses from community members in Port St. John in the Eastern Cape Province (ECP) of South Africa. Results obtained reveal similarities and some differences based on demographic characteristics with regards to the benefits of rural tourism to the community. Importantly, the study illuminates the fragmented way in which residents perceive tourism benefits, both from a gender perspective and personal benefit versus community dichotomy. The paper discusses policy as well as practical local economic development implications. Keywords: Rural tourism; community; Port St. Johns; inclusive development; sustainable development
- Full Text:
- Date Issued: 2021
An Analysis of Employee Motivation in a Multinational Context in Sub Saharan Africa
- Acha-Anyi, Paul Nkemngu, Masaraure, Robson
- Authors: Acha-Anyi, Paul Nkemngu , Masaraure, Robson
- Date: 2021
- Subjects: Employee motivation Sub-Saharan Africa Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7021 , vital:52757 , xlink:href=":https://doi.org/10.46222/ajhtl.19770720-119"
- Description: This study assesses motivational preferences of employees in a multinational context in Sub Saharan Africa. Using the Grundfos group operating sites in Ghana, Kenya and South Africa as a case study, the study explores quantitative data on possible differences in employee motivational factors based on selected variables such as location, length of service and managerial status. Questionnaires were employed in collecting data from 131 participants from the three locations of Grundfos Sub Saharan Africa (SSA). Results of the study reveal that the factor “equal treatment of employees” is considered most important among the respondents. It is also noted that there were no significant statistical differences among the participants based on the examined variables. Policy and practical implications of the findings of this study are discussed, particularly around the development and implementation of Human resources policies that address employee perceptions of equity. This study makes a contribution to existing literature on employee motivation in multinational settings. Keywords: Employee motivation, motivational factors, multinational context, Sub-Saharan Africa
- Full Text:
- Date Issued: 2021
- Authors: Acha-Anyi, Paul Nkemngu , Masaraure, Robson
- Date: 2021
- Subjects: Employee motivation Sub-Saharan Africa Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7021 , vital:52757 , xlink:href=":https://doi.org/10.46222/ajhtl.19770720-119"
- Description: This study assesses motivational preferences of employees in a multinational context in Sub Saharan Africa. Using the Grundfos group operating sites in Ghana, Kenya and South Africa as a case study, the study explores quantitative data on possible differences in employee motivational factors based on selected variables such as location, length of service and managerial status. Questionnaires were employed in collecting data from 131 participants from the three locations of Grundfos Sub Saharan Africa (SSA). Results of the study reveal that the factor “equal treatment of employees” is considered most important among the respondents. It is also noted that there were no significant statistical differences among the participants based on the examined variables. Policy and practical implications of the findings of this study are discussed, particularly around the development and implementation of Human resources policies that address employee perceptions of equity. This study makes a contribution to existing literature on employee motivation in multinational settings. Keywords: Employee motivation, motivational factors, multinational context, Sub-Saharan Africa
- Full Text:
- Date Issued: 2021
Graphene quantum dots functionalized with 4-amino-2, 2, 6, 6-tetramethylpiperidine-N-oxide as fluorescence “turn-on” nanosensors
- Achadu, Ojodomo J, Britton, Jonathan, Nyokong, Tebello
- Authors: Achadu, Ojodomo J , Britton, Jonathan , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239854 , vital:50773 , xlink:href="https://doi.org/10.1007/s10895-016-1916-y"
- Description: In this study, we report on the fabrication of simple and rapid graphene quantum dots (GQDs)-based fluorescence “turn-ON” nanoprobes for sensitive and selective detection of ascorbic acid (AA). Pristine GQDs and S and N co-doped-GQDs (SN-GQDs) were functionalized with 4-amino-2,2,6,6-tetramethylpiperidine-N-oxide (4-amino-TEMPO, a nitroxide free radical). The nitroxide free radicals efficiently quenched the fluorescence of the GQDs and upon interaction of the nanoconjugates with ascorbic acid, the quenched fluorescence was restored. The linear ranges recorded were 0.5–5.7 μM and 0.1–5.5 μM for GQDs-4-amino-TEMPO and SN-GQDs-4amino-TEMPO nanoprobes, respectively. Limits of detection were found to be 60 nM and 84 nM for SN-GQDS-4-amino-TEMPO and GQDs-4-amino-TEMPO for AA detection, respectively. This novel fluorescence “turn-ON” technique showed to be highly rapid and selective towards AA detection.
- Full Text:
- Date Issued: 2016
- Authors: Achadu, Ojodomo J , Britton, Jonathan , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239854 , vital:50773 , xlink:href="https://doi.org/10.1007/s10895-016-1916-y"
- Description: In this study, we report on the fabrication of simple and rapid graphene quantum dots (GQDs)-based fluorescence “turn-ON” nanoprobes for sensitive and selective detection of ascorbic acid (AA). Pristine GQDs and S and N co-doped-GQDs (SN-GQDs) were functionalized with 4-amino-2,2,6,6-tetramethylpiperidine-N-oxide (4-amino-TEMPO, a nitroxide free radical). The nitroxide free radicals efficiently quenched the fluorescence of the GQDs and upon interaction of the nanoconjugates with ascorbic acid, the quenched fluorescence was restored. The linear ranges recorded were 0.5–5.7 μM and 0.1–5.5 μM for GQDs-4-amino-TEMPO and SN-GQDs-4amino-TEMPO nanoprobes, respectively. Limits of detection were found to be 60 nM and 84 nM for SN-GQDS-4-amino-TEMPO and GQDs-4-amino-TEMPO for AA detection, respectively. This novel fluorescence “turn-ON” technique showed to be highly rapid and selective towards AA detection.
- Full Text:
- Date Issued: 2016
Fluorescence behaviour of supramolecular hybrids containing graphene quantum dots and pyrene-derivatized phthalocyanines and porphyrins
- Achadu, Ojodomo John, Managa, Muthumuni, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Managa, Muthumuni , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188953 , vital:44801 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.10.029"
- Description: Novel pyrene-derivatized zinc and cobalt phthalocyanines (Pcs) and porphyrins (Ps) were immobilized on graphene quantum dots (GQDs) to form GQDs-Pcs and GQDs-Ps supramolecular hybrids via the π–π stacking interaction method. Spectroscopic evidence shows that the resultant hybrids were stable owing to the strong π–π stacking interaction between the GQDs and the respective Pcs and Ps, thus leading to the fabrication of interesting and functional supramolecular hybrids by taking advantage of the delocalized π electron systems of GQDs and the macrocycles. The conjugates showed increased fluorescence quantum yields for the Pcs/Ps, but decreased values for the GQDs in the conjugates. These novel hybrid materials could potentially be deployed for studies in both fundamental and applied perspectives due to the synergistic contributions resulting from the combination of their excellent electronic and optical properties.
- Full Text:
- Date Issued: 2017
- Authors: Achadu, Ojodomo John , Managa, Muthumuni , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188953 , vital:44801 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.10.029"
- Description: Novel pyrene-derivatized zinc and cobalt phthalocyanines (Pcs) and porphyrins (Ps) were immobilized on graphene quantum dots (GQDs) to form GQDs-Pcs and GQDs-Ps supramolecular hybrids via the π–π stacking interaction method. Spectroscopic evidence shows that the resultant hybrids were stable owing to the strong π–π stacking interaction between the GQDs and the respective Pcs and Ps, thus leading to the fabrication of interesting and functional supramolecular hybrids by taking advantage of the delocalized π electron systems of GQDs and the macrocycles. The conjugates showed increased fluorescence quantum yields for the Pcs/Ps, but decreased values for the GQDs in the conjugates. These novel hybrid materials could potentially be deployed for studies in both fundamental and applied perspectives due to the synergistic contributions resulting from the combination of their excellent electronic and optical properties.
- Full Text:
- Date Issued: 2017
Interaction of graphene quantum dots with 4-acetamido-2, 2, 6, 6-tetramethylpiperidine-oxyl free radicals
- Achadu, Ojodomo John, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189031 , vital:44810 , xlink:href="https://doi.org/10.1007/s10895-015-1712-0"
- Description: We report on the interaction of graphene quantum dots (GQDs) with 4-acetamido-2,2,6,6-tetramethylpiperidineoxyl (4-acetamido-TEMPO) free radicals. The GQDs were N and S, N doped. The fluorescence quantum yields were higher for the doped GQDs compared to the undoped. The interaction is assessed by spectrofluorimetric, steady state/time resolved fluorescence and electron paramagnetic resonance (EPR) techniques. Fluorescence quenching was observed upon the addition of 4-acetamido-TEMPO to the GQDs. Photoinduced electron transfer (PET) mechanism was suggested as the plausible mechanism involved in the fluorescence quenching in which 4-acetamido-TEMPO acted as the electron acceptor.
- Full Text:
- Date Issued: 2016
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189031 , vital:44810 , xlink:href="https://doi.org/10.1007/s10895-015-1712-0"
- Description: We report on the interaction of graphene quantum dots (GQDs) with 4-acetamido-2,2,6,6-tetramethylpiperidineoxyl (4-acetamido-TEMPO) free radicals. The GQDs were N and S, N doped. The fluorescence quantum yields were higher for the doped GQDs compared to the undoped. The interaction is assessed by spectrofluorimetric, steady state/time resolved fluorescence and electron paramagnetic resonance (EPR) techniques. Fluorescence quenching was observed upon the addition of 4-acetamido-TEMPO to the GQDs. Photoinduced electron transfer (PET) mechanism was suggested as the plausible mechanism involved in the fluorescence quenching in which 4-acetamido-TEMPO acted as the electron acceptor.
- Full Text:
- Date Issued: 2016
The interaction between graphene quantum dots grafted with polyethyleneimine and Au@ Ag nanoparticles
- Achadu, Ojodomo John, Uddin, Imran, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Uddin, Imran , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188679 , vital:44775 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.03.016"
- Description: Graphene quantum dots grafted with polyethyleneimine (GQDs-PEI) and Au@Ag core-shell nanoparticles blend was demonstrated to be a novel biosensing nanoprobe for the rapid and highly sensitive detection of biothiols such as cysteine (Cys), homocysteine (Hcys) and glutathione (GSH). The fluorescence emission of GQDs-PEI was quenched efficiently upon interaction with Au@Ag core-shell nanoparticles. The quenched fluorescence emission of the GQDs-PEI was restored in the presence of the biothiols. The fluorimetric sensing is based on the strong affinity between the mercapto (SH) groups of the biothiols and the Au@Ag core-shell nanoparticles by which the interaction between GQDs-PEI and Au@Ag core-shell nanoparticles was disrupted with a consequent modulation (‘turn-on’) of the quenched GQDs-PEI emission. Thus, a new, simple, rapid and highly sensitive fluorescence nanoprobe for detecting biothiols has been developed in this work.
- Full Text:
- Date Issued: 2016
- Authors: Achadu, Ojodomo John , Uddin, Imran , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188679 , vital:44775 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.03.016"
- Description: Graphene quantum dots grafted with polyethyleneimine (GQDs-PEI) and Au@Ag core-shell nanoparticles blend was demonstrated to be a novel biosensing nanoprobe for the rapid and highly sensitive detection of biothiols such as cysteine (Cys), homocysteine (Hcys) and glutathione (GSH). The fluorescence emission of GQDs-PEI was quenched efficiently upon interaction with Au@Ag core-shell nanoparticles. The quenched fluorescence emission of the GQDs-PEI was restored in the presence of the biothiols. The fluorimetric sensing is based on the strong affinity between the mercapto (SH) groups of the biothiols and the Au@Ag core-shell nanoparticles by which the interaction between GQDs-PEI and Au@Ag core-shell nanoparticles was disrupted with a consequent modulation (‘turn-on’) of the quenched GQDs-PEI emission. Thus, a new, simple, rapid and highly sensitive fluorescence nanoprobe for detecting biothiols has been developed in this work.
- Full Text:
- Date Issued: 2016
Fluorescence behavior of nanoconjugates of graphene quantum dots and zinc phthalocyanines
- Achadu, Ojodomo John, Uddin, Imran, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Uddin, Imran , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188777 , vital:44784 , xlink:href="https://doi.org/10.1016/j.jphotochem.2015.11.006"
- Description: Graphene quantum dots (GQDs) and zinc phthalocyanines interactions in different modes (covalent and non-covalent) are reported in this study. GQDs were covalently attached to the following complexes: zinc tetraamino phthalocyanine (ZnTAPc) via amide coupling, zinc tetracarboxyphenoxy Pc (ZnTCPPc) (π–π interaction) and cationic zinc tetrapyridiloxy Pc (ZnTmPyPc) (ionic interaction). GQDs fluorescence was quenched in the presence of the ZnPc derivatives. The nanoensembles of GQDs–ZnPcs showed stimulated emissions of the ZnPcs. The suggested quenching mechanism is through Förster resonance energy transfer (FRET). These novel nanoensembles hold promise for various optical and luminescence based applications.
- Full Text:
- Date Issued: 2016
- Authors: Achadu, Ojodomo John , Uddin, Imran , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188777 , vital:44784 , xlink:href="https://doi.org/10.1016/j.jphotochem.2015.11.006"
- Description: Graphene quantum dots (GQDs) and zinc phthalocyanines interactions in different modes (covalent and non-covalent) are reported in this study. GQDs were covalently attached to the following complexes: zinc tetraamino phthalocyanine (ZnTAPc) via amide coupling, zinc tetracarboxyphenoxy Pc (ZnTCPPc) (π–π interaction) and cationic zinc tetrapyridiloxy Pc (ZnTmPyPc) (ionic interaction). GQDs fluorescence was quenched in the presence of the ZnPc derivatives. The nanoensembles of GQDs–ZnPcs showed stimulated emissions of the ZnPcs. The suggested quenching mechanism is through Förster resonance energy transfer (FRET). These novel nanoensembles hold promise for various optical and luminescence based applications.
- Full Text:
- Date Issued: 2016
Application of graphene quantum dots functionalized with thymine and thymine-appended zinc phthalocyanine as novel photoluminescent nanoprobes
- Achadu, Ojodomo John, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188508 , vital:44760 , xlink:href="https://doi.org/10.1039/C6NJ03285K"
- Description: Graphene quantum dots (GQDs) and zinc phthalocyanine (ZnPc) were separately modified with thymine to obtain thymine-functionalized GQDs (T-GQDs) and ZnPc (T-ZnPc). T-GQDs and nanoconjugates of T-ZnPc with pristine GQDs (represented as pristine GQDs–T-ZnPc) or T-GQDs (represented as T-GQDs–T-ZnPc) were employed as fluorescent probes for the detection of mercury(II) ions (Hg2+). The as-synthesized T-GQDs alone demonstrated a highly sensitive and selective fluorescence “turn-OFF” process for Hg2+ detection due to the specific interaction between the thymine functionality on the T-GQDs with Hg2+. On the other hand, the fluorescence of pristine GQDs and T-GQDs was quenched (“turn-OFF”) upon coordination with T-ZnPc. However, the fluorescence emission was selectively restored (“turn-ON” process) in the presence of Hg2+ resulting in the sensitive detection of Hg2+ in the nanomolar concentration range (limit of detection = 0.05 nM, for the pristine GQDs–T-ZnPc probe). The probe containing pristine GQDs and the T-ZnPc complex demonstrated a higher specific and sensitive recognition of Hg2+ as compared to the T-GQDs alone or T-GQDs–T-ZnPc probes which are ascribed to the fluorescence “turn-ON” process of the former. Screening of different metal ions and counter ions proved that the probes are specifically suited for Hg2+ detection.
- Full Text:
- Date Issued: 2017
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188508 , vital:44760 , xlink:href="https://doi.org/10.1039/C6NJ03285K"
- Description: Graphene quantum dots (GQDs) and zinc phthalocyanine (ZnPc) were separately modified with thymine to obtain thymine-functionalized GQDs (T-GQDs) and ZnPc (T-ZnPc). T-GQDs and nanoconjugates of T-ZnPc with pristine GQDs (represented as pristine GQDs–T-ZnPc) or T-GQDs (represented as T-GQDs–T-ZnPc) were employed as fluorescent probes for the detection of mercury(II) ions (Hg2+). The as-synthesized T-GQDs alone demonstrated a highly sensitive and selective fluorescence “turn-OFF” process for Hg2+ detection due to the specific interaction between the thymine functionality on the T-GQDs with Hg2+. On the other hand, the fluorescence of pristine GQDs and T-GQDs was quenched (“turn-OFF”) upon coordination with T-ZnPc. However, the fluorescence emission was selectively restored (“turn-ON” process) in the presence of Hg2+ resulting in the sensitive detection of Hg2+ in the nanomolar concentration range (limit of detection = 0.05 nM, for the pristine GQDs–T-ZnPc probe). The probe containing pristine GQDs and the T-ZnPc complex demonstrated a higher specific and sensitive recognition of Hg2+ as compared to the T-GQDs alone or T-GQDs–T-ZnPc probes which are ascribed to the fluorescence “turn-ON” process of the former. Screening of different metal ions and counter ions proved that the probes are specifically suited for Hg2+ detection.
- Full Text:
- Date Issued: 2017
Graphene quantum dots decorated with maleimide and zinc tetramaleimido-phthalocyanine: Application in the design of “OFF-ON” fluorescence sensors for biothiols
- Achadu, Ojodomo John, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188282 , vital:44741 , xlink:href="https://doi.org/10.1016/j.talanta.2017.01.031"
- Description: The fabrication of maleimide-derivatized graphene quantum dots (M-GQDs) and zinc phthalocyanine (2) as novel sensor probes for the selective detection of biothiols (cysteine, homocysteine or glutathione) through the rapid and specific Michael addition reaction between biothiols and the maleimide-derivatized probes is presented in this study. GQDs directly functionalized with maleimide units (M-GQDs) were synthesized and deployed for biothiols recognition following the principle of Michael addition. M-GQDs probe was found to be highly sensitive and selective towards biothiols detection in the nanomolar range in aqueous solution and at physiological pH (7.0). On the other hand, non-covalent interaction between pristine GQDs and novel zinc tetramaleimido-derivatized phthalocyanine resulted in the quenching of the pristine GQDs fluorescence emission which was switched back to the “ON” mode by Michael addition mechanism in the presence of biothiols. Tested relevant biomolecules did not interfere in the quantitative recognition of the biothiols. The probes showed to be highly sensitive, specific and selective for biothiols sensing in simulated real samples.
- Full Text:
- Date Issued: 2017
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188282 , vital:44741 , xlink:href="https://doi.org/10.1016/j.talanta.2017.01.031"
- Description: The fabrication of maleimide-derivatized graphene quantum dots (M-GQDs) and zinc phthalocyanine (2) as novel sensor probes for the selective detection of biothiols (cysteine, homocysteine or glutathione) through the rapid and specific Michael addition reaction between biothiols and the maleimide-derivatized probes is presented in this study. GQDs directly functionalized with maleimide units (M-GQDs) were synthesized and deployed for biothiols recognition following the principle of Michael addition. M-GQDs probe was found to be highly sensitive and selective towards biothiols detection in the nanomolar range in aqueous solution and at physiological pH (7.0). On the other hand, non-covalent interaction between pristine GQDs and novel zinc tetramaleimido-derivatized phthalocyanine resulted in the quenching of the pristine GQDs fluorescence emission which was switched back to the “ON” mode by Michael addition mechanism in the presence of biothiols. Tested relevant biomolecules did not interfere in the quantitative recognition of the biothiols. The probes showed to be highly sensitive, specific and selective for biothiols sensing in simulated real samples.
- Full Text:
- Date Issued: 2017
Graphene quantum dots coordinated to mercaptopyridine-substituted phthalocyanines: Characterization and application as fluorescence “turn ON” nanoprobes
- Achadu, Ojodomo John, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188293 , vital:44742 , xlink:href="https://doi.org/10.1016/j.saa.2016.11.043"
- Description: This study reports on the design of novel nanoconjugates of graphene quantum dots (GQDs) and tetra or octa-mercaptopyridine-substituted zinc and aluminium phthalocyanines (Pcs) deployed as fluorescence “turn ON” nanoprobes. The phthalocyanines were separately adsorbed onto the planar structure of graphene quantum dots (GQDs) via π-π stacking interaction to form GQDs-mercaptopyridine Pcs nanoconjugates. The quaternized Pc complexes could also interact with the GQDs through electrostatic attraction due to the positive charges on the Pcs ring substituents and the negative charges on the surface of GQDs. The fluorescence emission of the GQDs was quenched upon coordination to the respective Pcs. However, the fluorescence emission was “turned ON” in the presence of Hg2 + employed as a test analyte. The mechanism of the “turn ON” of the GQDs emission in the nanoconjugates is ascribed to the strong affinity of Hg2 + to bind with the bridging sulfur on the Pcs periphery thereby disrupting the π-π stacking interaction between the GQDs and the Pcs with a consequent “turn ON” of the coordinated GQDs' fluorescence.
- Full Text:
- Date Issued: 2017
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188293 , vital:44742 , xlink:href="https://doi.org/10.1016/j.saa.2016.11.043"
- Description: This study reports on the design of novel nanoconjugates of graphene quantum dots (GQDs) and tetra or octa-mercaptopyridine-substituted zinc and aluminium phthalocyanines (Pcs) deployed as fluorescence “turn ON” nanoprobes. The phthalocyanines were separately adsorbed onto the planar structure of graphene quantum dots (GQDs) via π-π stacking interaction to form GQDs-mercaptopyridine Pcs nanoconjugates. The quaternized Pc complexes could also interact with the GQDs through electrostatic attraction due to the positive charges on the Pcs ring substituents and the negative charges on the surface of GQDs. The fluorescence emission of the GQDs was quenched upon coordination to the respective Pcs. However, the fluorescence emission was “turned ON” in the presence of Hg2 + employed as a test analyte. The mechanism of the “turn ON” of the GQDs emission in the nanoconjugates is ascribed to the strong affinity of Hg2 + to bind with the bridging sulfur on the Pcs periphery thereby disrupting the π-π stacking interaction between the GQDs and the Pcs with a consequent “turn ON” of the coordinated GQDs' fluorescence.
- Full Text:
- Date Issued: 2017
Graphene quantum dots anchored onto mercaptopyridine-substituted zinc phthalocyanine-Au@ Ag nanoparticle hybrid: Application as fluorescence “off-on-off” sensor for Hg2+ and biothiols
- Achadu, Ojodomo John, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188194 , vital:44731 , xlink:href="https://doi.org/10.1016/j.dyepig.2017.06.002"
- Description: Novel supramolecular hybrid containing polyethyleneimine-functionalized graphene quantum dots (PEI-GQDs) and mercaptopyridine-substituted zinc phthalocyanine (Pc)-Au@Ag nano-alloys is presented in this study. The designed hybrid was employed as a dual fluorescence nanoprobe for Hg2+ and biothiol detection in aqueous solution using PEI-GQDs as the fluorescence switching signal probe. The dual sensing platform for the analytes detection is firstly, based on the quenching (turn “OFF”) of the PEI-GQDs fluorescence upon π-π interaction or electrostatic attraction with Pc-Au@Ag conjugate. The quenched fluorescence can be switched back to the “ON” mode in the presence of Hg2+ and switched “OFF” again when biothiols are introduced to capture the Hg2+ ion via the formation of the strong metal-thiol bond (Hg-S). The “off-on-off” processes were modulated by different amounts of Hg2+ and biothiols. The nanoprobes were found to be highly stable and selective towards the target analytes in the presence of other amino acids and metal ions. Also, the probes were successfully deployed in the assay of the test analytes in spiked samples.
- Full Text:
- Date Issued: 2017
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188194 , vital:44731 , xlink:href="https://doi.org/10.1016/j.dyepig.2017.06.002"
- Description: Novel supramolecular hybrid containing polyethyleneimine-functionalized graphene quantum dots (PEI-GQDs) and mercaptopyridine-substituted zinc phthalocyanine (Pc)-Au@Ag nano-alloys is presented in this study. The designed hybrid was employed as a dual fluorescence nanoprobe for Hg2+ and biothiol detection in aqueous solution using PEI-GQDs as the fluorescence switching signal probe. The dual sensing platform for the analytes detection is firstly, based on the quenching (turn “OFF”) of the PEI-GQDs fluorescence upon π-π interaction or electrostatic attraction with Pc-Au@Ag conjugate. The quenched fluorescence can be switched back to the “ON” mode in the presence of Hg2+ and switched “OFF” again when biothiols are introduced to capture the Hg2+ ion via the formation of the strong metal-thiol bond (Hg-S). The “off-on-off” processes were modulated by different amounts of Hg2+ and biothiols. The nanoprobes were found to be highly stable and selective towards the target analytes in the presence of other amino acids and metal ions. Also, the probes were successfully deployed in the assay of the test analytes in spiked samples.
- Full Text:
- Date Issued: 2017
Fluorescence “turn-ON” nanosensor for cyanide ion using supramolecular hybrid of graphene quantum dots and cobalt pyrene-derivatized phthalocyanine
- Achadu, Ojodomo John, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187594 , vital:44674 , xlink:href="https://doi.org/10.1016/j.dyepig.2018.08.038"
- Description: A functional hybrid of graphene quantum dots (GQDs) and cobalt pyrene-derivatized phthalocyanine (CoPc) used as a sensitive nanoprobe for the recognition of cyanide ion (CN−) is described in this work. The fluorescence of GQDs was quenched upon non-covalent (π-π stacking) hybrid formation with CoPc via a possible energy transfer pathway. However, in the presence of CN−, the interaction between GQDs and CoPc was perturbed, such that the fluorescence of GQDs initially quenched by CoPc was found to be efficiently recovered in the presence of CN−. Amongst the molecules and anions tested to ascertain their effects on the fluorescence behaviour of the hybrid, only CN− ion induced the tunable “off-on” restoration of the fluorescence of GQDs, which demonstrates the selectivity of the hybrid towards CN−. The restored fluorescence signals of the GQDs were linearly modulated by different concentrations of CN− and were used for the quantitative assay of CN− with high sensitivity coupled with rapid detection time. The detection was in the linear range of 1.0–50.0 nM with limits of detection (LOD) of 0.5 nM. The analysis of spiked samples for the recovery of CN− further demonstrated the applicability of the hybrid for the satisfactory detection of the target analyte.
- Full Text:
- Date Issued: 2019
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187594 , vital:44674 , xlink:href="https://doi.org/10.1016/j.dyepig.2018.08.038"
- Description: A functional hybrid of graphene quantum dots (GQDs) and cobalt pyrene-derivatized phthalocyanine (CoPc) used as a sensitive nanoprobe for the recognition of cyanide ion (CN−) is described in this work. The fluorescence of GQDs was quenched upon non-covalent (π-π stacking) hybrid formation with CoPc via a possible energy transfer pathway. However, in the presence of CN−, the interaction between GQDs and CoPc was perturbed, such that the fluorescence of GQDs initially quenched by CoPc was found to be efficiently recovered in the presence of CN−. Amongst the molecules and anions tested to ascertain their effects on the fluorescence behaviour of the hybrid, only CN− ion induced the tunable “off-on” restoration of the fluorescence of GQDs, which demonstrates the selectivity of the hybrid towards CN−. The restored fluorescence signals of the GQDs were linearly modulated by different concentrations of CN− and were used for the quantitative assay of CN− with high sensitivity coupled with rapid detection time. The detection was in the linear range of 1.0–50.0 nM with limits of detection (LOD) of 0.5 nM. The analysis of spiked samples for the recovery of CN− further demonstrated the applicability of the hybrid for the satisfactory detection of the target analyte.
- Full Text:
- Date Issued: 2019
SDF-1 and PDGF enhance αvβ5-mediated ERK activation and adhesion-independent growth of human pre-B cell lines:
- Acharya, Mridu, Edkins, Adrienne L, Ozanne, B, Cushley, W
- Authors: Acharya, Mridu , Edkins, Adrienne L , Ozanne, B , Cushley, W
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165044 , vital:41204 , DOI: 10.1038/leu.2009.126
- Description: CD23 acts through the αvβ5 integrin to promote growth of human pre-B cell lines in an adhesion-independent manner. αvβ5 is expressed on normal B-cell precursors in the bone marrow. Soluble CD23 (sCD23), short CD23-derived peptides containing the arg-lys-cys (RKC) motif recognized by αvβ5 and anti-αvβ5 monoclonal antibodies (MAbs) all sustain growth of pre-B cell lines. The chemokine stromal cell-derived factor-1 (SDF-1) regulates key processes during B-cell development. SDF-1 enhanced the growth-sustaining effect driven by ligation of αvβ5 with anti-αvβ5 MAb 15F-11, sCD23 or CD23-derived RKC-containing peptides. This effect was restricted to B-cell precursors and was specific to SDF-1.
- Full Text:
- Date Issued: 2009
- Authors: Acharya, Mridu , Edkins, Adrienne L , Ozanne, B , Cushley, W
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165044 , vital:41204 , DOI: 10.1038/leu.2009.126
- Description: CD23 acts through the αvβ5 integrin to promote growth of human pre-B cell lines in an adhesion-independent manner. αvβ5 is expressed on normal B-cell precursors in the bone marrow. Soluble CD23 (sCD23), short CD23-derived peptides containing the arg-lys-cys (RKC) motif recognized by αvβ5 and anti-αvβ5 monoclonal antibodies (MAbs) all sustain growth of pre-B cell lines. The chemokine stromal cell-derived factor-1 (SDF-1) regulates key processes during B-cell development. SDF-1 enhanced the growth-sustaining effect driven by ligation of αvβ5 with anti-αvβ5 MAb 15F-11, sCD23 or CD23-derived RKC-containing peptides. This effect was restricted to B-cell precursors and was specific to SDF-1.
- Full Text:
- Date Issued: 2009