Oral Phytothymol ameliorates the stress induced IBS symptoms
- Subramaniyam, Selvaraj, Yang, Shuyou, Diallo, Bakary N, Fanshu, Xu, Lei, Luo, Li, Chong, Tastan-Bishop, Özlem, Bhattacharyya, Sanjib
- Authors: Subramaniyam, Selvaraj , Yang, Shuyou , Diallo, Bakary N , Fanshu, Xu , Lei, Luo , Li, Chong , Tastan-Bishop, Özlem , Bhattacharyya, Sanjib
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426034 , vital:72308 , xlink:href="https://doi.org/10.1038/s41598-020-70420-4"
- Description: Physical stressors play a crucial role in the progression of irritable bowel syndrome (IBS). Here we report a heterogeneous physical stress induced IBS rat model which shows depression and subsequent modulation of IBS by oral treatment of thymol. Oral administration of Thymol reduces the stress induced IBS significantly altering the stress induced gastrointestinal hypermotility, prolonged the whole gut transit time, and increased abdominal withdrawal reflex suggesting gastrointestinal hypermotility and visceral discomfort caused the onset of depression. Immunohistochemical analysis in small intestine and colon of rats shows the decreased 5-HT3AR expression level while thymol treatment normalized the 5-HT3AR expression in the stressed rats. Molecular docking studies showed that thymol competes with endogenous serotonin and an antagonist, Tropisetron and all have similar binding energies to 5-HT3AR. Molecular dynamics simulations revealed that thymol and tropisetron might have similar effects on 5-HT3AR. Our study suggest that thymol improves IBS symptoms through 5-HT3AR, could be useful for the treatment of IBS.
- Full Text:
- Date Issued: 2020
- Authors: Subramaniyam, Selvaraj , Yang, Shuyou , Diallo, Bakary N , Fanshu, Xu , Lei, Luo , Li, Chong , Tastan-Bishop, Özlem , Bhattacharyya, Sanjib
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426034 , vital:72308 , xlink:href="https://doi.org/10.1038/s41598-020-70420-4"
- Description: Physical stressors play a crucial role in the progression of irritable bowel syndrome (IBS). Here we report a heterogeneous physical stress induced IBS rat model which shows depression and subsequent modulation of IBS by oral treatment of thymol. Oral administration of Thymol reduces the stress induced IBS significantly altering the stress induced gastrointestinal hypermotility, prolonged the whole gut transit time, and increased abdominal withdrawal reflex suggesting gastrointestinal hypermotility and visceral discomfort caused the onset of depression. Immunohistochemical analysis in small intestine and colon of rats shows the decreased 5-HT3AR expression level while thymol treatment normalized the 5-HT3AR expression in the stressed rats. Molecular docking studies showed that thymol competes with endogenous serotonin and an antagonist, Tropisetron and all have similar binding energies to 5-HT3AR. Molecular dynamics simulations revealed that thymol and tropisetron might have similar effects on 5-HT3AR. Our study suggest that thymol improves IBS symptoms through 5-HT3AR, could be useful for the treatment of IBS.
- Full Text:
- Date Issued: 2020
Paul Ashwin Transforming university education, a manifesto: A review
- Authors: McKenna, Sioux
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185886 , vital:44445 , xlink:href="https://doi.org/10.1007/s10734-020-00641-z"
- Description: This book is wide-ranging in its focus. It tackles student-centeredness, graduate premiums, credentialing, quality assurance, big data and rankings, and yet it offers a coherent engagement with these and many other contemporary issues. The coherence is brought about by the consistent application of one central idea throughout the book. That is that the value of higher education for both the individual and for society is that it brings the graduate into a transformational relationship with knowledge that changes their sense of who they are and thereby makes possible their doing all number of things in the world.
- Full Text:
- Date Issued: 2020
- Authors: McKenna, Sioux
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185886 , vital:44445 , xlink:href="https://doi.org/10.1007/s10734-020-00641-z"
- Description: This book is wide-ranging in its focus. It tackles student-centeredness, graduate premiums, credentialing, quality assurance, big data and rankings, and yet it offers a coherent engagement with these and many other contemporary issues. The coherence is brought about by the consistent application of one central idea throughout the book. That is that the value of higher education for both the individual and for society is that it brings the graduate into a transformational relationship with knowledge that changes their sense of who they are and thereby makes possible their doing all number of things in the world.
- Full Text:
- Date Issued: 2020
Perceived benefits of nature-based experiences as mediators of connectedness with nature: The case of Mystic Mountain
- Ward-Smith, Chesney, Naidoo, Tony, Olvitt, Lausanne L, Olvitt, Lausanne, Akhurst, Jacqueline
- Authors: Ward-Smith, Chesney , Naidoo, Tony , Olvitt, Lausanne L , Olvitt, Lausanne , Akhurst, Jacqueline
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/372782 , vital:66622 , xlink:href="https://doi.org/10.1177/00812463209470"
- Description: Perceived nature disconnection lies at the heart of the world’s socio-ecological crisis. Finding ways to reconnect with nature is fundamental towards reducing the adverse psychological–social– ecological consequences of this disconnection. Understanding the psychological and social benefits of nature-based experiences is important towards actualising reconnection. This article discusses such benefits for child and adult participants from the Eastern Cape, South Africa. This work stems from Ecopsychology research with an outdoor education centre, Mystic Mountain. The experiences of two groups of children (n=25, aged 10–14years) and adult instructors (n=12, aged 18–50years) were explored using interpretive case-study methodology. Through semi-structured interviews and focus groups, participant observation, and reflexive journaling, data were collected and analysed thematically. This article centralises participants’ perceived psychological and social benefits of nature-based experiences as mediators of deeper self and nature connectedness. Integrating these benefits into nature-based pedagogy-design processes could contribute towards more effective enhancements of nature connectedness, and in turn, foster Earth’s larger flourishment.
- Full Text:
- Date Issued: 2020
- Authors: Ward-Smith, Chesney , Naidoo, Tony , Olvitt, Lausanne L , Olvitt, Lausanne , Akhurst, Jacqueline
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/372782 , vital:66622 , xlink:href="https://doi.org/10.1177/00812463209470"
- Description: Perceived nature disconnection lies at the heart of the world’s socio-ecological crisis. Finding ways to reconnect with nature is fundamental towards reducing the adverse psychological–social– ecological consequences of this disconnection. Understanding the psychological and social benefits of nature-based experiences is important towards actualising reconnection. This article discusses such benefits for child and adult participants from the Eastern Cape, South Africa. This work stems from Ecopsychology research with an outdoor education centre, Mystic Mountain. The experiences of two groups of children (n=25, aged 10–14years) and adult instructors (n=12, aged 18–50years) were explored using interpretive case-study methodology. Through semi-structured interviews and focus groups, participant observation, and reflexive journaling, data were collected and analysed thematically. This article centralises participants’ perceived psychological and social benefits of nature-based experiences as mediators of deeper self and nature connectedness. Integrating these benefits into nature-based pedagogy-design processes could contribute towards more effective enhancements of nature connectedness, and in turn, foster Earth’s larger flourishment.
- Full Text:
- Date Issued: 2020
Photodynamic activity of 2, 6-diiodo-3, 5-dithienylvinyleneBODIPYs and their folate-functionalized chitosan-coated Pluronic® F-127 micelles on MCF-7 breast cancer cells
- Molupe, Nthabeleng, Babu, Balaji, Oluwole, David O, Prinsloo, Earl, Gai, Lizhi, Shen, Zhen, Mack, John, Nyokong, Tebello
- Authors: Molupe, Nthabeleng , Babu, Balaji , Oluwole, David O , Prinsloo, Earl , Gai, Lizhi , Shen, Zhen , Mack, John , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186222 , vital:44474 , xlink:href="https://doi.org/10.1142/S1088424619501773"
- Description: A 2,6-diiodo-3,5-dithienylvinyleneBODIPY dye was prepared and encapsulated with folate-chitosan capped Pluronic®® F-127 to provide drug delivery systems for photodynamic therapy (PDT). Moderately enhanced singlet oxygen quantum yields were observed for the dye encapsulation complexes in water. The in vitro dark cytotoxicity and photodynamic activity were investigated on the human breast adenocarcinoma (MCF-7) cell line. Minimal dark cytotoxicity was observed for the BODIPY dyes in 5% DMSO and when encapsulated in folate-functionalized chitosan-coated Pluronic®® F-127 micelles, since the cell viability values are consistently greater than 80% over the 0-40 μg⋅mL−1μg⋅mL−1 concentration range. Upon irradiation of the samples, significant cytocidal activity was observed for the encapsulation complex of a 2,6-diiodo-8-dimethylaminophenyl-3,5-dithienylvinyleneBODIPY dye with less than 50% viable cells observed at concentrations ≥20μg⋅mL−1≥20μg⋅mL−1.
- Full Text:
- Date Issued: 2020
- Authors: Molupe, Nthabeleng , Babu, Balaji , Oluwole, David O , Prinsloo, Earl , Gai, Lizhi , Shen, Zhen , Mack, John , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186222 , vital:44474 , xlink:href="https://doi.org/10.1142/S1088424619501773"
- Description: A 2,6-diiodo-3,5-dithienylvinyleneBODIPY dye was prepared and encapsulated with folate-chitosan capped Pluronic®® F-127 to provide drug delivery systems for photodynamic therapy (PDT). Moderately enhanced singlet oxygen quantum yields were observed for the dye encapsulation complexes in water. The in vitro dark cytotoxicity and photodynamic activity were investigated on the human breast adenocarcinoma (MCF-7) cell line. Minimal dark cytotoxicity was observed for the BODIPY dyes in 5% DMSO and when encapsulated in folate-functionalized chitosan-coated Pluronic®® F-127 micelles, since the cell viability values are consistently greater than 80% over the 0-40 μg⋅mL−1μg⋅mL−1 concentration range. Upon irradiation of the samples, significant cytocidal activity was observed for the encapsulation complex of a 2,6-diiodo-8-dimethylaminophenyl-3,5-dithienylvinyleneBODIPY dye with less than 50% viable cells observed at concentrations ≥20μg⋅mL−1≥20μg⋅mL−1.
- Full Text:
- Date Issued: 2020
Photodynamic antimicrobial chemotherapy of a dimethylamino-functionalized asymmetric zinc (II) phthalocyanine and its quaternized derivative against Staphylococcus aureus when supported on asymmetric polystyrene polymer membranes
- Mafukidze, Donovan M, Nyokong, Tebello
- Authors: Mafukidze, Donovan M , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186168 , vital:44470 , xlink:href="https://doi.org/10.1016/j.reactfunctpolym.2020.104634"
- Description: Membrane applications are hindered by fouling. Photoactive membranes (containing photosensitizers) show photodynamic antimicrobial chemotherapy (PACT) activity which reduces biological fouling. In this work we use phthalocyanines (Pcs) as photosensitizers. The Pcs used are: 2-(4-carboxyphenoxy)-9(10), 16(17), 23(24)-tris(dimethylamino) phthalocyaninato zinc(II) (1) and the quaternized 2-(4-carboxyphenoxy)-9(10), 16(17), 23(24)-tris(trimethylamino) phthalocyanine zinc(II) methyl sulfate (2). Complex 2 showed an enhanced singlet oxygen quantum yield (ΦΔ) of 0.76 compared to 0.53 for 1. Complex 2 showed enhanced PACT activity against Staphylococcus aureus giving a log reduction value of 9.4, while its precursor (complex 1) gave 0.08. The complexes were then conjugated to amine-functionalized polystyrene and embedded into polystyrene to form membranes resulting in ΦΔ values of 0.24 and 0.27 for complexes 1 and 2 respectively in water. The latter membrane showed better PACT activity.
- Full Text:
- Date Issued: 2020
- Authors: Mafukidze, Donovan M , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186168 , vital:44470 , xlink:href="https://doi.org/10.1016/j.reactfunctpolym.2020.104634"
- Description: Membrane applications are hindered by fouling. Photoactive membranes (containing photosensitizers) show photodynamic antimicrobial chemotherapy (PACT) activity which reduces biological fouling. In this work we use phthalocyanines (Pcs) as photosensitizers. The Pcs used are: 2-(4-carboxyphenoxy)-9(10), 16(17), 23(24)-tris(dimethylamino) phthalocyaninato zinc(II) (1) and the quaternized 2-(4-carboxyphenoxy)-9(10), 16(17), 23(24)-tris(trimethylamino) phthalocyanine zinc(II) methyl sulfate (2). Complex 2 showed an enhanced singlet oxygen quantum yield (ΦΔ) of 0.76 compared to 0.53 for 1. Complex 2 showed enhanced PACT activity against Staphylococcus aureus giving a log reduction value of 9.4, while its precursor (complex 1) gave 0.08. The complexes were then conjugated to amine-functionalized polystyrene and embedded into polystyrene to form membranes resulting in ΦΔ values of 0.24 and 0.27 for complexes 1 and 2 respectively in water. The latter membrane showed better PACT activity.
- Full Text:
- Date Issued: 2020
Photodynamic antimicrobial chemotherapy of asymmetric porphyrin-silver conjugates towards photoinactivation of Staphylococcus aureus
- Shabangu, Samuel M, Babu, Balaji, Soy, Rodah C, Managa, Muthumuni, Sekhosana, Kutloano E, Nyokong, Tebello
- Authors: Shabangu, Samuel M , Babu, Balaji , Soy, Rodah C , Managa, Muthumuni , Sekhosana, Kutloano E , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186536 , vital:44509 , xlink:href="https://doi.org/10.1080/00958972.2020.1739273"
- Description: Asymmetric mono-carboxy-porphyrins, (5-(4-carboxyphenyl)10,15, 20-tris(pentafluorophenyl)porphyrinato zinc(II) (1), 5-(4- carboxyphenyl)10,15,20-triphenylporphyrinato zinc(II) (2) and 5-(4- carboxyphenyl)10,15,20-tris(2-thienyl)porphyrinato zinc(II) (3), were linked to Ag nanoparticles (AgNPs) through amide bonds and selfassembly (the latter only for 3). The porphyrins and conjugates were used for photodynamic antimicrobial chemotherapy (PACT) against Staphylococcus aureus. PACT uses singlet oxygen for antimicrobial activity. Complex 3 and its conjugates had higher singlet oxygen quantum yields and higher log reduction when compared with the rest of the porphyrins and corresponding conjugates. These high log reductions for 3 and its conjugate were attributed to the presence of sulfur groups whereby there was more interaction with the bacterial membrane.
- Full Text:
- Date Issued: 2020
- Authors: Shabangu, Samuel M , Babu, Balaji , Soy, Rodah C , Managa, Muthumuni , Sekhosana, Kutloano E , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186536 , vital:44509 , xlink:href="https://doi.org/10.1080/00958972.2020.1739273"
- Description: Asymmetric mono-carboxy-porphyrins, (5-(4-carboxyphenyl)10,15, 20-tris(pentafluorophenyl)porphyrinato zinc(II) (1), 5-(4- carboxyphenyl)10,15,20-triphenylporphyrinato zinc(II) (2) and 5-(4- carboxyphenyl)10,15,20-tris(2-thienyl)porphyrinato zinc(II) (3), were linked to Ag nanoparticles (AgNPs) through amide bonds and selfassembly (the latter only for 3). The porphyrins and conjugates were used for photodynamic antimicrobial chemotherapy (PACT) against Staphylococcus aureus. PACT uses singlet oxygen for antimicrobial activity. Complex 3 and its conjugates had higher singlet oxygen quantum yields and higher log reduction when compared with the rest of the porphyrins and corresponding conjugates. These high log reductions for 3 and its conjugate were attributed to the presence of sulfur groups whereby there was more interaction with the bacterial membrane.
- Full Text:
- Date Issued: 2020
Photophysical and nonlinear optical properties of the positional isomers of 4-(4-tertbutylphenoxy) substituted cobalt, nickel and copper phthalocyanines
- Neduvhuledza, Zelda, Nkaki, Thabo, Louzada, Marcel, Nyokong, Tebello, Khene, Samson M
- Authors: Neduvhuledza, Zelda , Nkaki, Thabo , Louzada, Marcel , Nyokong, Tebello , Khene, Samson M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186067 , vital:44460 , xlink:href="https://doi.org/10.1016/j.optmat.2020.110195"
- Description: This paper reports on the third order nonlinear optical properties of cobalt, nickel and tetrakis(4- terbutylphenoxy)phthalocyaninatocopper(II) isomers, using the Z-scan technique. Metal-free isomers were found to have high nonlinear absorption coefficient (β) values compared to the metalated isomers. Metal-free C2v isomer was found to have the highest β value of 1.52 × 10− 10 mMW− 1 in THF. All the metal-free and metal phthalocyanine isomers nonlinear properties were found to be dependent on the singlet state absorption. Imaginary second order nonlinear hyperpolarizability (Im[γ]), ground state cross section (σg), excited states cross sections (σs and σt) and two photon absorption (TPA) cross section (σTPA) values are reported in this work. The five-energy level model rate equations were used to model the nonlinear response and absorption cross sections.
- Full Text:
- Date Issued: 2020
- Authors: Neduvhuledza, Zelda , Nkaki, Thabo , Louzada, Marcel , Nyokong, Tebello , Khene, Samson M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186067 , vital:44460 , xlink:href="https://doi.org/10.1016/j.optmat.2020.110195"
- Description: This paper reports on the third order nonlinear optical properties of cobalt, nickel and tetrakis(4- terbutylphenoxy)phthalocyaninatocopper(II) isomers, using the Z-scan technique. Metal-free isomers were found to have high nonlinear absorption coefficient (β) values compared to the metalated isomers. Metal-free C2v isomer was found to have the highest β value of 1.52 × 10− 10 mMW− 1 in THF. All the metal-free and metal phthalocyanine isomers nonlinear properties were found to be dependent on the singlet state absorption. Imaginary second order nonlinear hyperpolarizability (Im[γ]), ground state cross section (σg), excited states cross sections (σs and σt) and two photon absorption (TPA) cross section (σTPA) values are reported in this work. The five-energy level model rate equations were used to model the nonlinear response and absorption cross sections.
- Full Text:
- Date Issued: 2020
Photophysico-chemical properties and photoinactivation of Staphylococcus Aureus using zinc phthalocyanines linked silver nanoparticles conjugates
- Matlou, Gauta G, Nyokong, Tebello
- Authors: Matlou, Gauta G , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186278 , vital:44481 , xlink:href="https://doi.org/10.1016/j.dyepig.2020.108237"
- Description: The synthesis of zinc (II) tri (tert-butyl phenoxy) mono cinnamic acid Pc (complex 1) is reported for the first time in this work. Complex 1 and the reported zinc (II) tri (tert-butyl), mono cinnamic acid phthalocyanine (2), zinc (II) mono cinnamic acid substituted phthalocyanine (3) and zinc (II) tetra cinnamic acid substituted phthalocyanine (4) are conjugated to cysteine capped silver nanoparticles (cys-AgNPs) through an amide bond. The photophysicochemical properties and the photodynamic antimicrobial chemotherapy (PACT) activities of the Pc-cys-AgNPs conjugates and the Pcs alone on S. Aureus are reported. Improved triplet and singlet oxygen quantum yields were observed for the conjugated complexes compared to Pcs alone, due to the heavy atom effect of cys-AgNPs. Asymmetric complexes 1,2, 3 and their respective conjugates recorded higher photosensitizing properties and PACT activities compared to 4 and 4-cys-AgNPs, respectively. Higher log reductions and percentage reductions of S. Aureus were recorded for conjugated complexes compared to ZnPcs only, showing enhanced PACT activities due to their higher singlet oxygen quantum yields.
- Full Text:
- Date Issued: 2020
- Authors: Matlou, Gauta G , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186278 , vital:44481 , xlink:href="https://doi.org/10.1016/j.dyepig.2020.108237"
- Description: The synthesis of zinc (II) tri (tert-butyl phenoxy) mono cinnamic acid Pc (complex 1) is reported for the first time in this work. Complex 1 and the reported zinc (II) tri (tert-butyl), mono cinnamic acid phthalocyanine (2), zinc (II) mono cinnamic acid substituted phthalocyanine (3) and zinc (II) tetra cinnamic acid substituted phthalocyanine (4) are conjugated to cysteine capped silver nanoparticles (cys-AgNPs) through an amide bond. The photophysicochemical properties and the photodynamic antimicrobial chemotherapy (PACT) activities of the Pc-cys-AgNPs conjugates and the Pcs alone on S. Aureus are reported. Improved triplet and singlet oxygen quantum yields were observed for the conjugated complexes compared to Pcs alone, due to the heavy atom effect of cys-AgNPs. Asymmetric complexes 1,2, 3 and their respective conjugates recorded higher photosensitizing properties and PACT activities compared to 4 and 4-cys-AgNPs, respectively. Higher log reductions and percentage reductions of S. Aureus were recorded for conjugated complexes compared to ZnPcs only, showing enhanced PACT activities due to their higher singlet oxygen quantum yields.
- Full Text:
- Date Issued: 2020
Preformulation studies of efavirenz with lipid excipients using thermal and spectroscopic techniques
- Makoni, Pedzisai A, Kasongo, Kasongo W, Walker, Roderick B
- Authors: Makoni, Pedzisai A , Kasongo, Kasongo W , Walker, Roderick B
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183253 , vital:43934 , xlink:href=" https://doi.org/10.1691/ph.2020.0053"
- Description: Investigation and identification of potential lipids for the manufacture of efavirenz loaded solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) was undertaken. Polymorphic modification and characteristics of the lipids with the best solubilising potential for efavirenz was explored using Fourier Transform Infrared Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC) and Wide-angle X-ray Scattering (WAXS). Lipid screening revealed that EFV is highly soluble in solid and liquid lipids, with glyceryl monostearate (GM) and Transcutol® HP (THP) exhibiting the best solubilising potential for EFV. GM exists in a stable β-polymorphic modification prior to exposure to heat, but exists in an α-polymorphic modification following exposure to heat. However, it was established that the addition of THP to GM revealed the co-existence of the α- and β'-polymorphic modifications of the lipid. EFV (60% w/w) exists in a crystalline state in a 70:30 mixture of GM and THP. Investigation of binary mixtures of EFV/GM and GM/THP, in addition to eutectic mixtures of EFV, GM and THP using FT-IR, DSC and WAXS revealed no potential interactions between EFV and the lipids selected for the production of the nanocarriers.
- Full Text:
- Date Issued: 2020
Preformulation studies of efavirenz with lipid excipients using thermal and spectroscopic techniques
- Authors: Makoni, Pedzisai A , Kasongo, Kasongo W , Walker, Roderick B
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183253 , vital:43934 , xlink:href=" https://doi.org/10.1691/ph.2020.0053"
- Description: Investigation and identification of potential lipids for the manufacture of efavirenz loaded solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) was undertaken. Polymorphic modification and characteristics of the lipids with the best solubilising potential for efavirenz was explored using Fourier Transform Infrared Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC) and Wide-angle X-ray Scattering (WAXS). Lipid screening revealed that EFV is highly soluble in solid and liquid lipids, with glyceryl monostearate (GM) and Transcutol® HP (THP) exhibiting the best solubilising potential for EFV. GM exists in a stable β-polymorphic modification prior to exposure to heat, but exists in an α-polymorphic modification following exposure to heat. However, it was established that the addition of THP to GM revealed the co-existence of the α- and β'-polymorphic modifications of the lipid. EFV (60% w/w) exists in a crystalline state in a 70:30 mixture of GM and THP. Investigation of binary mixtures of EFV/GM and GM/THP, in addition to eutectic mixtures of EFV, GM and THP using FT-IR, DSC and WAXS revealed no potential interactions between EFV and the lipids selected for the production of the nanocarriers.
- Full Text:
- Date Issued: 2020
Prioritising African perspectives in psychiatric genomics research
- Kamaara, Eunice, Kong, Camillia, Campbell, Megan
- Authors: Kamaara, Eunice , Kong, Camillia , Campbell, Megan
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302520 , vital:58204 , xlink:href="https://doi.org/10.1111/dewb.12248"
- Description: Psychiatric genomics research with African populations comes with a range of practical challenges around translation of psychiatric genomics research concepts, procedures, and nosology. These challenges raise deep ethical issues particularly around legitimacy of informed consent, a core foundation of research ethics. Through aconsideration of the constitutive function of language, the paper problematises like‐for‐like, designative translations which often involve the ‘indigenization’ of English terms or use of metaphors which misrepresent the risks and benefits of research. This paper argues that effective translation of psychiatric genomics research terminology in African contexts demands substantive engagement with African conceptual schemas and values. In developing attenuated forms of translational thinking, researchers may recognise the deeper motivational reasons behind participation in research, highlighting the possibility that such reasons may depart from the original meaning implied within informed consent forms. These translational issues might be ameliorated with a critical re-examination of how researchers develop and present protocols to institutional ethics review boards.
- Full Text:
- Date Issued: 2020
- Authors: Kamaara, Eunice , Kong, Camillia , Campbell, Megan
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302520 , vital:58204 , xlink:href="https://doi.org/10.1111/dewb.12248"
- Description: Psychiatric genomics research with African populations comes with a range of practical challenges around translation of psychiatric genomics research concepts, procedures, and nosology. These challenges raise deep ethical issues particularly around legitimacy of informed consent, a core foundation of research ethics. Through aconsideration of the constitutive function of language, the paper problematises like‐for‐like, designative translations which often involve the ‘indigenization’ of English terms or use of metaphors which misrepresent the risks and benefits of research. This paper argues that effective translation of psychiatric genomics research terminology in African contexts demands substantive engagement with African conceptual schemas and values. In developing attenuated forms of translational thinking, researchers may recognise the deeper motivational reasons behind participation in research, highlighting the possibility that such reasons may depart from the original meaning implied within informed consent forms. These translational issues might be ameliorated with a critical re-examination of how researchers develop and present protocols to institutional ethics review boards.
- Full Text:
- Date Issued: 2020
Prospects for the biological control of Iris pseudacorus L(Iridaceae)
- Minuti, Gianmarco, Coetzee, Julie A, Ngxande-Koza, Samella, Hill, Martin P, Stiers, Iris
- Authors: Minuti, Gianmarco , Coetzee, Julie A , Ngxande-Koza, Samella , Hill, Martin P , Stiers, Iris
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417776 , vital:71485 , xlink:href="https://doi.org/10.1080/09583157.2020.1853050"
- Description: Native to Europe, North Africa and western Asia, Iris pseudacorus L. (Iridaceae) has invaded natural and human-modified wetlands worldwide. This species is considered a noxious weed in several countries including Argentina, South Africa and New Zealand. Its broad ecological tolerance, high resilience and reproductive potential make current mechanical and chemical control measures cost-ineffective, and biological control is considered a suitable alternative. In order to prioritise candidate biocontrol agents, a list of organisms reported to attack the plant within its native range has been assembled, and information about their host-range and damaging potential gathered from the literature. Furthermore, surveys for natural enemies of the plant were conducted in Belgium and northern Italy. The insect fauna associated with I. pseudacorus at the sites surveyed comprised mostly incidental visitors and polyphagous feeders, with the exception of the sawfly Rhadinoceraea micans Klug (Hymenoptera: Tenthredinidae), the seed weevil Mononychus punctumalbum Herbst (Coleoptera: Curculionidae), and the flea beetle Aphthona nonstriata Goeze (Coleoptera: Chrysomelidae). The potential of these species for biocontrol was evaluated, and A. nonstriata was given highest priority. A population of this species was imported to quarantine in South Africa, where it is currently undergoing host-specificity testing. Importation of the two remaining candidates is expected shortly. In conclusion, the prospects for the biological control of I. pseudacorus appear promising.
- Full Text:
- Date Issued: 2020
- Authors: Minuti, Gianmarco , Coetzee, Julie A , Ngxande-Koza, Samella , Hill, Martin P , Stiers, Iris
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417776 , vital:71485 , xlink:href="https://doi.org/10.1080/09583157.2020.1853050"
- Description: Native to Europe, North Africa and western Asia, Iris pseudacorus L. (Iridaceae) has invaded natural and human-modified wetlands worldwide. This species is considered a noxious weed in several countries including Argentina, South Africa and New Zealand. Its broad ecological tolerance, high resilience and reproductive potential make current mechanical and chemical control measures cost-ineffective, and biological control is considered a suitable alternative. In order to prioritise candidate biocontrol agents, a list of organisms reported to attack the plant within its native range has been assembled, and information about their host-range and damaging potential gathered from the literature. Furthermore, surveys for natural enemies of the plant were conducted in Belgium and northern Italy. The insect fauna associated with I. pseudacorus at the sites surveyed comprised mostly incidental visitors and polyphagous feeders, with the exception of the sawfly Rhadinoceraea micans Klug (Hymenoptera: Tenthredinidae), the seed weevil Mononychus punctumalbum Herbst (Coleoptera: Curculionidae), and the flea beetle Aphthona nonstriata Goeze (Coleoptera: Chrysomelidae). The potential of these species for biocontrol was evaluated, and A. nonstriata was given highest priority. A population of this species was imported to quarantine in South Africa, where it is currently undergoing host-specificity testing. Importation of the two remaining candidates is expected shortly. In conclusion, the prospects for the biological control of I. pseudacorus appear promising.
- Full Text:
- Date Issued: 2020
Reimagining academic identities in response to research demands at Universities of Technology
- Gumbi, Thobani, McKenna, Sioux
- Authors: Gumbi, Thobani , McKenna, Sioux
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185897 , vital:44446 , xlink:href="https://doi.org/10.14426/cristal.v8i1.234"
- Description: In the last volume of this journal, Garraway and Winberg called for a reimagination of Universities of Technology (UoT) within the South African higher education system. This article continues that conversation by looking at the implications that the formation of the UoT had for academics’ identities. Technikon lecturers’ identities were closely tied to workplace expertise, but demands for research in UoTs have changed this. A social realist analysis of interviews with fifteen academics at three UoTs finds that research remains a contested issue. Interviewees understood research to take the form of acquiring postgraduate qualifications, rather than as an ongoing activity tied to their identities. Echoing Garraway and Winberg’s study, the bureaucratic nature of the institutional culture was referred to as a constraint. There was also a view that for this programme, Dental Technology, a demand for research was needed from industry if this was to be a valued aspect of academics’ identities.
- Full Text:
- Date Issued: 2020
- Authors: Gumbi, Thobani , McKenna, Sioux
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185897 , vital:44446 , xlink:href="https://doi.org/10.14426/cristal.v8i1.234"
- Description: In the last volume of this journal, Garraway and Winberg called for a reimagination of Universities of Technology (UoT) within the South African higher education system. This article continues that conversation by looking at the implications that the formation of the UoT had for academics’ identities. Technikon lecturers’ identities were closely tied to workplace expertise, but demands for research in UoTs have changed this. A social realist analysis of interviews with fifteen academics at three UoTs finds that research remains a contested issue. Interviewees understood research to take the form of acquiring postgraduate qualifications, rather than as an ongoing activity tied to their identities. Echoing Garraway and Winberg’s study, the bureaucratic nature of the institutional culture was referred to as a constraint. There was also a view that for this programme, Dental Technology, a demand for research was needed from industry if this was to be a valued aspect of academics’ identities.
- Full Text:
- Date Issued: 2020
Relational hubs for collaborative landscape stewardship
- Cockburn, Jessica, Cundill, Georgina, Shackleton, Sheona, Cele, Ayanda, Cornelius, Susanna F, Koopman, Vaughan, Le Roux, Jean-Pierre, McLeod, Nicky, Rouget, Mathieu, Schroder, Samantha, Van den Broek, Dieter, Wright, Dale R, Zwinkelse, Marijn
- Authors: Cockburn, Jessica , Cundill, Georgina , Shackleton, Sheona , Cele, Ayanda , Cornelius, Susanna F , Koopman, Vaughan , Le Roux, Jean-Pierre , McLeod, Nicky , Rouget, Mathieu , Schroder, Samantha , Van den Broek, Dieter , Wright, Dale R , Zwinkelse, Marijn
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/392748 , vital:68789 , xlink:href="https://doi.org/10.1080/08941920.2019.1658141"
- Description: Landscape stewardship is considered an important place-based approach to addressing sustainability challenges. Working at landscape-level requires collaboration between diverse landscape stakeholders. In this study, we partnered with local stewardship practitioners across six cases in South Africa to investigate how they facilitate collaboration towards social-ecological sustainability outcomes. We found that practitioners facilitate collaboration among stakeholders by operating as relational hubs in the landscape. Through these hubs, they build new inter-personal relationships among stakeholders, creating social networks which enable stewardship practice. The hubs deepen human-nature relationships by creating enabling conditions for stewards to put stewardship ethics into action. Drawing on insights from these cases, we call for a relational approach to landscape stewardship which focuses on human-to-human and human-to-nature relationships. Moreover, we argue that landscape stewardship initiatives need to re-focus stewardship on stewards, recognizing them as key agents of change in addressing the conflict between agriculture and conservation inherent in many landscapes.
- Full Text:
- Date Issued: 2020
- Authors: Cockburn, Jessica , Cundill, Georgina , Shackleton, Sheona , Cele, Ayanda , Cornelius, Susanna F , Koopman, Vaughan , Le Roux, Jean-Pierre , McLeod, Nicky , Rouget, Mathieu , Schroder, Samantha , Van den Broek, Dieter , Wright, Dale R , Zwinkelse, Marijn
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/392748 , vital:68789 , xlink:href="https://doi.org/10.1080/08941920.2019.1658141"
- Description: Landscape stewardship is considered an important place-based approach to addressing sustainability challenges. Working at landscape-level requires collaboration between diverse landscape stakeholders. In this study, we partnered with local stewardship practitioners across six cases in South Africa to investigate how they facilitate collaboration towards social-ecological sustainability outcomes. We found that practitioners facilitate collaboration among stakeholders by operating as relational hubs in the landscape. Through these hubs, they build new inter-personal relationships among stakeholders, creating social networks which enable stewardship practice. The hubs deepen human-nature relationships by creating enabling conditions for stewards to put stewardship ethics into action. Drawing on insights from these cases, we call for a relational approach to landscape stewardship which focuses on human-to-human and human-to-nature relationships. Moreover, we argue that landscape stewardship initiatives need to re-focus stewardship on stewards, recognizing them as key agents of change in addressing the conflict between agriculture and conservation inherent in many landscapes.
- Full Text:
- Date Issued: 2020
Screening for small molecule modulators of Trypanosoma brucei Hsp70 chaperone activity based upon alcyonarian coral-derived natural products
- Andreassend, Sarah K, Bentley, Stephen, Blatch, Gregory L, Boshoff, Aileen, Keyzers, Robert A
- Authors: Andreassend, Sarah K , Bentley, Stephen , Blatch, Gregory L , Boshoff, Aileen , Keyzers, Robert A
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426045 , vital:72309 , xlink:href="https://doi.org/10.3390/md18020081"
- Description: The Trypanosoma brucei Hsp70/J-protein machinery plays an essential role in survival, differentiation, and pathogenesis of the protozoan parasite, and is an emerging target against African Trypanosomiasis. This study evaluated a set of small molecules, inspired by the malonganenones and nuttingins, as modulators of the chaperone activity of the cytosolic heat inducible T. brucei Hsp70 and constitutive TbHsp70.4 proteins. The compounds were assessed for cytotoxicity on both the bloodstream form of T. b. brucei parasites and a mammalian cell line. The compounds were then investigated for their modulatory effect on the aggregation suppression and ATPase activities of the TbHsp70 proteins. A structure–activity relationship for the malonganenone-class of alkaloids is proposed based upon these results.
- Full Text:
- Date Issued: 2020
- Authors: Andreassend, Sarah K , Bentley, Stephen , Blatch, Gregory L , Boshoff, Aileen , Keyzers, Robert A
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426045 , vital:72309 , xlink:href="https://doi.org/10.3390/md18020081"
- Description: The Trypanosoma brucei Hsp70/J-protein machinery plays an essential role in survival, differentiation, and pathogenesis of the protozoan parasite, and is an emerging target against African Trypanosomiasis. This study evaluated a set of small molecules, inspired by the malonganenones and nuttingins, as modulators of the chaperone activity of the cytosolic heat inducible T. brucei Hsp70 and constitutive TbHsp70.4 proteins. The compounds were assessed for cytotoxicity on both the bloodstream form of T. b. brucei parasites and a mammalian cell line. The compounds were then investigated for their modulatory effect on the aggregation suppression and ATPase activities of the TbHsp70 proteins. A structure–activity relationship for the malonganenone-class of alkaloids is proposed based upon these results.
- Full Text:
- Date Issued: 2020
Screening of ectomycorrhizal and other associated fungi in South African forest nurseries
- Chartier FitzGerald , Veronique, Dames, Joanna F, Hawley, Greer L
- Authors: Chartier FitzGerald , Veronique , Dames, Joanna F , Hawley, Greer L
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426058 , vital:72310 , xlink:href="https://hdl.handle.net/10520/ejc-soufor-v82-n4-a8"
- Description: The South African forestry industry covers approximately 1.3 million hectares and is dependent on exotic pine and eucalypt species. Nursery seedlings are not inoculated with ectomycorrhizal (ECM) fungi. This investigation assessed levels of naturally occurring ECM colonisation of Pinus patula seedlings from 10 different South African forestry nurseries using a grid line intersect method. Fungi from colonised roots were identified using morphological characteristics and Illumina sequencing. Colonisation of seedlings in production nurseries was low (2-21%). Morphologically, the ECM fungi Thelophora terrestris, Suillus sibiricus, and the genera Russula and Pseudotomentella were identified. Molecularly, the ECM fungi T. terrestris, Inocybe jacobi and the genus Sphaerosporella, as well as several other ECM-containing families were identified, along with many saprotrophic/ endophytic fungi belonging to genera such as Penicillium, Ramasonia and Talaromyces. As can be seen, a combination of both molecular and morphological identification techniques are needed as neither is able to give a full picture of the species present in isolation. This study reveals an initial insight into the root microbiome community associated with Pinus patula seedlings, which should be taken into account when inoculation with beneficial microbes is considered. It determined that natural ECM fungal root colonisation levels are very low throughout the South African nurseries investigated, indicating the need for ECM fungal inoculation, which can increase seedling growth, viability and resistance to pathogens.
- Full Text:
- Date Issued: 2020
- Authors: Chartier FitzGerald , Veronique , Dames, Joanna F , Hawley, Greer L
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426058 , vital:72310 , xlink:href="https://hdl.handle.net/10520/ejc-soufor-v82-n4-a8"
- Description: The South African forestry industry covers approximately 1.3 million hectares and is dependent on exotic pine and eucalypt species. Nursery seedlings are not inoculated with ectomycorrhizal (ECM) fungi. This investigation assessed levels of naturally occurring ECM colonisation of Pinus patula seedlings from 10 different South African forestry nurseries using a grid line intersect method. Fungi from colonised roots were identified using morphological characteristics and Illumina sequencing. Colonisation of seedlings in production nurseries was low (2-21%). Morphologically, the ECM fungi Thelophora terrestris, Suillus sibiricus, and the genera Russula and Pseudotomentella were identified. Molecularly, the ECM fungi T. terrestris, Inocybe jacobi and the genus Sphaerosporella, as well as several other ECM-containing families were identified, along with many saprotrophic/ endophytic fungi belonging to genera such as Penicillium, Ramasonia and Talaromyces. As can be seen, a combination of both molecular and morphological identification techniques are needed as neither is able to give a full picture of the species present in isolation. This study reveals an initial insight into the root microbiome community associated with Pinus patula seedlings, which should be taken into account when inoculation with beneficial microbes is considered. It determined that natural ECM fungal root colonisation levels are very low throughout the South African nurseries investigated, indicating the need for ECM fungal inoculation, which can increase seedling growth, viability and resistance to pathogens.
- Full Text:
- Date Issued: 2020
Sn (iv) N-confused porphyrins as photosensitizer dyes for photodynamic therapy in the near IR region
- Babu, Balaji, Mack, John, Nyokong, Tebello
- Authors: Babu, Balaji , Mack, John , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186648 , vital:44521 , xlink:href="https://doi.org/10.1039/D0DT03296D"
- Description: The utility of Sn(IV) N-confused porphyrin (SnNCP) for use as photosensitizer dyes in photodynamic therapy is investigated. SnNCP has an unusually high singlet oxygen quantum yield of 0.72 in DMSO. IC50 values of 1.6 and 12.8 μM were obtained against MCF-7 cells upon irradiation with 660 and 780 nm LEDs.
- Full Text:
- Date Issued: 2020
Sn (iv) N-confused porphyrins as photosensitizer dyes for photodynamic therapy in the near IR region
- Authors: Babu, Balaji , Mack, John , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186648 , vital:44521 , xlink:href="https://doi.org/10.1039/D0DT03296D"
- Description: The utility of Sn(IV) N-confused porphyrin (SnNCP) for use as photosensitizer dyes in photodynamic therapy is investigated. SnNCP has an unusually high singlet oxygen quantum yield of 0.72 in DMSO. IC50 values of 1.6 and 12.8 μM were obtained against MCF-7 cells upon irradiation with 660 and 780 nm LEDs.
- Full Text:
- Date Issued: 2020
Substituent effect on the photophysical and nonlinear optical characteristics of Si phthalocyanine–Detonated nanodiamond conjugated systems in solution
- Matshitse, Refilwe, Nyokong, Tebello
- Authors: Matshitse, Refilwe , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186293 , vital:44482 , xlink:href="https://doi.org/10.1016/j.ica.2020.119447"
- Description: This work reports on the photophysical, nonlinear absorption and optical limiting properties of detonation nanodiamonds (DNDs)-silicon phthalocyanine nanoconjugate systems. Si(IV) hydroxide phthalocyanines employed are: 2,9(10),16(17),23(24)-tetrakis-(4-pyridyloxy) phthalocyaninato (Si(OH)2TPPc), 2,9(10),16(17),23(24)-tetrakis-(4-tert-butyl) phthalocyanato (Si(OH)2TBPc) and phthalocyanato(Si(OH)2Pc). Pcs were covalently linked to nanondiamonds and investigated using 532 nm laser excitation at 7 ns pulses for their optical limiting properties. Si(OH)2TBPc and Si(OH)2Pc gave larger triplet quantum yields when linked to DNDs, while the value decreased for Si(OH)2TPPc in the presence of DNDs due to aggregation. However all Pcs showed enhanced nonlinear optical properties in the presence of DNDs. DNDs-Si(OH)2TPPc and DNDs-Si (OH)2TBPc gave the highest imaginary third-order susceptibility (Im[X(3)]) and hyperpolarizability (γ) at 5.19 × 10−8 and 3.85 × 10−8 esu and 2.66 × 10−27 and 1.97 × 10−27 esu, respectively. DNDs-Si(OH)2TBPc nanoconjugates showed lowest limiting threshold (Ilim) value of 0.01 J.cm−2 relative to 0.09 for DNDs-Si (OH)2TPPc.
- Full Text:
- Date Issued: 2020
- Authors: Matshitse, Refilwe , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186293 , vital:44482 , xlink:href="https://doi.org/10.1016/j.ica.2020.119447"
- Description: This work reports on the photophysical, nonlinear absorption and optical limiting properties of detonation nanodiamonds (DNDs)-silicon phthalocyanine nanoconjugate systems. Si(IV) hydroxide phthalocyanines employed are: 2,9(10),16(17),23(24)-tetrakis-(4-pyridyloxy) phthalocyaninato (Si(OH)2TPPc), 2,9(10),16(17),23(24)-tetrakis-(4-tert-butyl) phthalocyanato (Si(OH)2TBPc) and phthalocyanato(Si(OH)2Pc). Pcs were covalently linked to nanondiamonds and investigated using 532 nm laser excitation at 7 ns pulses for their optical limiting properties. Si(OH)2TBPc and Si(OH)2Pc gave larger triplet quantum yields when linked to DNDs, while the value decreased for Si(OH)2TPPc in the presence of DNDs due to aggregation. However all Pcs showed enhanced nonlinear optical properties in the presence of DNDs. DNDs-Si(OH)2TPPc and DNDs-Si (OH)2TBPc gave the highest imaginary third-order susceptibility (Im[X(3)]) and hyperpolarizability (γ) at 5.19 × 10−8 and 3.85 × 10−8 esu and 2.66 × 10−27 and 1.97 × 10−27 esu, respectively. DNDs-Si(OH)2TBPc nanoconjugates showed lowest limiting threshold (Ilim) value of 0.01 J.cm−2 relative to 0.09 for DNDs-Si (OH)2TPPc.
- Full Text:
- Date Issued: 2020
Susceptibility of Staphylococcus aureus to porphyrin-silver nanoparticle mediated photodynamic antimicrobial chemotherapy
- Shabangu, Samuel M, Babu, Balaji, Soy, Rodah C, Ovim, James, Amuhaya, Edith, Nyokong, Tebello
- Authors: Shabangu, Samuel M , Babu, Balaji , Soy, Rodah C , Ovim, James , Amuhaya, Edith , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186262 , vital:44479 , xlink:href="https://doi.org/10.1016/j.jlumin.2020.117158"
- Description: Photodynamic antimicrobial chemotherapy (PACT) is employed against multi drug resistant Staphylococcus aureus using porphyrins combined with silver nanoparticles to bring about a combined photodynamic effect. We employ Zn-meso-5,10,15,20-tetra(4-pyridyl) (1), Zn-meso-5,10,15,20-tetrathienyl (2), and Zn-meso-5-(4- hydroxyphenyl)- 10,15,20-tris(2-thienyl)(3) porphyrins and their self-assembled conjugates with silver nanoparticles for PACT against Staphylococcus aureus. Complex 3 with nanoparticles was found to perform better resulting in 0% bacterial viability at 60 min.
- Full Text:
- Date Issued: 2020
- Authors: Shabangu, Samuel M , Babu, Balaji , Soy, Rodah C , Ovim, James , Amuhaya, Edith , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186262 , vital:44479 , xlink:href="https://doi.org/10.1016/j.jlumin.2020.117158"
- Description: Photodynamic antimicrobial chemotherapy (PACT) is employed against multi drug resistant Staphylococcus aureus using porphyrins combined with silver nanoparticles to bring about a combined photodynamic effect. We employ Zn-meso-5,10,15,20-tetra(4-pyridyl) (1), Zn-meso-5,10,15,20-tetrathienyl (2), and Zn-meso-5-(4- hydroxyphenyl)- 10,15,20-tris(2-thienyl)(3) porphyrins and their self-assembled conjugates with silver nanoparticles for PACT against Staphylococcus aureus. Complex 3 with nanoparticles was found to perform better resulting in 0% bacterial viability at 60 min.
- Full Text:
- Date Issued: 2020
Synergistic effects of temperature and plant quality, on development time, size and lipid in Eccritotarsus eichhorniae
- Ismail, Mohannad, Brooks, Margot, Van Baaren, Joan, Albittar, Loulou
- Authors: Ismail, Mohannad , Brooks, Margot , Van Baaren, Joan , Albittar, Loulou
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426078 , vital:72312 , xlink:href="https://doi.org/10.1111/jen.12841"
- Description: Body size is an important biotic factor in evolutionary ecology, since it affects all aspects of insect physiology, life history and, consequently, fitness in ectothermic insects and how species adapt with their environment. It has been linked to tem-perature, with lower temperatures resulting in larger size. In this study, we tested the combined impact of temperature and plant quality on the body size, and de-velopment time from egg to adult of Eccritotarsus eichhorniae (Hemiptera: Miridae), an herbivorous insect used as a biological control agent against the invasive aquatic weed, water hyacinth Eichhornia crassipes (Pontederiaceae). We quantified insect size in individuals exposed to three temperatures (20, 25 and 30°C) combined with three qualities of host plant (high, medium and low) by calculating development time and measuring four traits: tibia length, forewing length, dry body mass and lipid con-tent, and we also determined the wing loading index. The development time, dry body mass and lipid content decreased linearly with increasing temperature and de-creasing plant quality. The decrease in size was the greatest when high temperature interacted with low plant quality. Smaller individuals had proportionately less lipid content. Wing loading decreased significantly with lower quality of host plant, result-ing in individuals likely to have theoretically higher flight ability. The results support the temperature-size rule (TSR) and that plant quality could influence the relationship between development time and the TSR. Results also provide novel evidence for a possible food quality-size rule for both sexes.
- Full Text:
- Date Issued: 2020
- Authors: Ismail, Mohannad , Brooks, Margot , Van Baaren, Joan , Albittar, Loulou
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426078 , vital:72312 , xlink:href="https://doi.org/10.1111/jen.12841"
- Description: Body size is an important biotic factor in evolutionary ecology, since it affects all aspects of insect physiology, life history and, consequently, fitness in ectothermic insects and how species adapt with their environment. It has been linked to tem-perature, with lower temperatures resulting in larger size. In this study, we tested the combined impact of temperature and plant quality on the body size, and de-velopment time from egg to adult of Eccritotarsus eichhorniae (Hemiptera: Miridae), an herbivorous insect used as a biological control agent against the invasive aquatic weed, water hyacinth Eichhornia crassipes (Pontederiaceae). We quantified insect size in individuals exposed to three temperatures (20, 25 and 30°C) combined with three qualities of host plant (high, medium and low) by calculating development time and measuring four traits: tibia length, forewing length, dry body mass and lipid con-tent, and we also determined the wing loading index. The development time, dry body mass and lipid content decreased linearly with increasing temperature and de-creasing plant quality. The decrease in size was the greatest when high temperature interacted with low plant quality. Smaller individuals had proportionately less lipid content. Wing loading decreased significantly with lower quality of host plant, result-ing in individuals likely to have theoretically higher flight ability. The results support the temperature-size rule (TSR) and that plant quality could influence the relationship between development time and the TSR. Results also provide novel evidence for a possible food quality-size rule for both sexes.
- Full Text:
- Date Issued: 2020
Synthesis and biological evaluation of bis-N2, N2′-(4-hydroxycoumarin-3-yl) ethylidene]-2, 3-dihydroxysuccinodihydrazides
- Manyeruke, Meloddy H, Tshiwawa, Thendamudzimu, Hoppe, Heinrich, Isaacs, Michelle, Seldon, Ronnett, Warner, Digby F, Krause, Rui W M, Kaye, Perry T
- Authors: Manyeruke, Meloddy H , Tshiwawa, Thendamudzimu , Hoppe, Heinrich , Isaacs, Michelle , Seldon, Ronnett , Warner, Digby F , Krause, Rui W M , Kaye, Perry T
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193430 , vital:45331 , xlink:href="https://doi.org/10.1016/j.bmcl.2019.126911"
- Description: A series of N2,N2′-bis[4-hydroxycoumarin-3-yl)ethylidene]-2,3-dihydroxysuccino-hydrazides, containing 4-hydroxycoumarin, hydrazine and tartaric acid moieties, have been prepared and examined for possible biological activity. Several of these compounds exhibit promising HIV-1 integrase inhibition (IC50 = 3.5 μM), and anti-T. brucei (32% viability) and anti-mycobacterial (Visual MIC90 = 15.63 μM) activity.
- Full Text:
- Date Issued: 2020
- Authors: Manyeruke, Meloddy H , Tshiwawa, Thendamudzimu , Hoppe, Heinrich , Isaacs, Michelle , Seldon, Ronnett , Warner, Digby F , Krause, Rui W M , Kaye, Perry T
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193430 , vital:45331 , xlink:href="https://doi.org/10.1016/j.bmcl.2019.126911"
- Description: A series of N2,N2′-bis[4-hydroxycoumarin-3-yl)ethylidene]-2,3-dihydroxysuccino-hydrazides, containing 4-hydroxycoumarin, hydrazine and tartaric acid moieties, have been prepared and examined for possible biological activity. Several of these compounds exhibit promising HIV-1 integrase inhibition (IC50 = 3.5 μM), and anti-T. brucei (32% viability) and anti-mycobacterial (Visual MIC90 = 15.63 μM) activity.
- Full Text:
- Date Issued: 2020