Sex work: discussion document 27-29 March 2012
- Authors: Congress of South African Trade Unions (COSATU)
- Date: 2012
- Subjects: Uncatalogued
- Language: English
- Type: book , text
- Identifier: http://hdl.handle.net/10962/68748 , vital:29311
- Description: The aim of this paper is to resuscitate the debate on the need for decriminalization of sex work and ensure that COSATU and its affiliates further engage within structures, alliance, non -governmental organizations and with the Government in terms of the need for law reform and identify alternative policy framework. However, whatever outcome of the legal processes pertaining to sex work, should be abide by the spirit of the Constitution which is committed to advancing human rights and social justice. Sex work in South Africa is currently criminalised and is restricted by the Sexual Offences Act of 1957 (an un-amended apartheid-era law) which prohibits all activities associated with it. The criminal offences related to sex work include amongst them the keeping or participating in the management of a brothel, procuring someone to become a sex worker, soliciting or selling sex or living of the earnings of a sex worker. In 2007 through the Sexual Offences Act their clients were also criminalised In 2007, the Act was amended to criminalise buyers of sexual services too (SALRC 2009). We therefore argue that the existing laws on sex work are nothing but hypocrisy of the conservatives and elites. They do not improve the conditions of women; instead they worsen the miserable conditions that women in the sex trade already find themselves in. The missing fact is that sex work is a by-product of our patriarchal capitalist society-not something created by some “immoral prostitute” The current oppressive legislation on sex work has stimulated a lot of debates and has led to an upsurge in advocacy work by individuals and organizations around the need to either legalise or decriminalize sex work. Likewise, Cosatu as a key civil society player has also played a leading role in its endeavor to unite the working class and to defend workers from exploitation as well as finding workable solutions to the plight of the most vulnerable people in our society who find themselves with no choice but to engage in sex work. The sex industry is by nature exploitative and inherently dangerous. Women in the industry experience different degrees of abuse, coercion and violence, but all of them are harmed physically and psychologically. As a trade union movement, COSATU has an interest in the debate about sex work, from the point of view that sex work targets mainly the working class and the poor, predominantly black women. High levels of unemployment, poverty and gender inequality are key factors driving sex work. The global economic crisis has aggravated the situation for the poor majority through job losses, casualisation and ultimately increased feminization of poverty. Cosatu has already started some debates and campaigns aimed at devising ways of protecting sex workers through collective workers struggles. As such, the sex work discourse and campaign among Cosatu affiliates for decriminalization was tabled at the Federation’s 10th Congress though it was deferred because of contestation and opposition amongst delegates. However, affiliates had the responsibility to go back and make further consultations, sensitization with their structures and open up a discussion at the level of the COSATU Central Executive Committee. Indeed, it is high time that the debate on decriminalization should be concluded and that sex work be recognized as work as Arnott and Crago (2009) argue that: “The criminalisation of sex work has precluded the enforcement and protection of sex workers’ Labour rights. This disregard for sex workers as workers has left many of those employed in brothels in South Africa vulnerable to labor abuses such as withheld wages, arbitrary fines, restrictions on mobility, and confiscation of belongings including medication. Sex workers on the street or working in brothels and other agencies have no recourse if customers refuse to pay them’’1 The decriminalization of sex work should take the course of a rights- based approach which means that sex workers would be able to enjoy their basic human & labour rights and be protected against sexual harassment, violence, rape and unfair working conditions. By so doing, sex workers would be able to access non-discriminatory health care services, be more empowered and operate within the ambit of protective labour and occupational health & safety laws.
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- Date Issued: 2012
Single walled carbon nanotubes functionalized with nickel phthalocyanines
- Authors: Khene, Samson , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/245843 , vital:51410 , xlink:href="https://doi.org/10.1142/S1088424611004439"
- Description: In this work we report on electrochemical behavior of nickel phthalocyanine derivatives tetrasubstituted peripherally and non-peripherally with hydroxy and used to modify single walled carbon nanotubes. Nickel phthalocyanine complex octasubstituted at the peripheral positions with hydroxy groups was also used to modify single walled carbon nanotubes. Nickel phthalocyanine complex tetrasubstituted with amino groups at peripheral position was covalently and non-covalently linked to single walled carbon nanotubes. All the conjugates of nickel phthalocyanine derivatives with single walled carbon nanotubes were used for the electro oxidation of 4-chlorophenol. The nickel phthalocyanine octabsubstituted with hydroxy groups at the non-peripheral positions gave the best current response and the best resistance against electrode fouling for the oxidation of 4-chlorophenol.
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- Date Issued: 2012
Social recruiting: a next generation social engineering attack
- Authors: Schoeman, A H B , Irwin, Barry V W
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428600 , vital:72523 , https://www.jstor.org/stable/26486876
- Description: Social engineering attacks initially experienced success due to the lack of understanding of the attack vector and resultant lack of remedial actions. Due to an increase in media coverage corporate bodies have begun to defend their interests from this vector. This has resulted in a new generation of social engineering attacks that have adapted to the industry response. These new forms of attack take into account the increased likelihood that they will be detected; rendering traditional defences against social engineering attacks moot. This paper highlights these attacks and will explain why traditional defences fail to address them as well as suggest new methods of incident response.
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- Date Issued: 2012
Spectral, photophysical and photochemical properties of tetra-and octaglycosylated zinc phthalocyanines
- Authors: Iqbal, Zafar , Masilela, Nkosiphile , Nyokong, Tebello , Lyubimtsev, Alexey , Hanack, Michael , Ziegler, Thomas
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/244428 , vital:51256 , xlink:href="https://doi.org/10.1039/c2pp05348a"
- Description: Photophysical and photochemical properties of a series of tetra- and octaglycosylated zinc phthalocyanines (ZnPcs) substituted with glucose and galactose moieties have been reported. Spectral properties of these phthalocyanines are compared in DMSO. Absorption spectra of the non-peripherally tetra-substituted ZnPcs 2 showed a significant red shift in their Q-band maxima as compared to the peripherally substituted analog 1. All the complexes gave high triplet quantum yields ranging from 0.68 to 0.88, whereas triplet lifetimes were in the range of 100–430 µs in argon-saturated solutions. The octagalactosylated ZnPc 3b showed the highest triplet quantum yield and singlet oxygen quantum yield of 0.88 and 0.69, respectively. The fluorescence quantum yields and lifetimes of all the compounds under investigation were within the range of zinc phthalocyanine complexes.
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- Date Issued: 2012
Spectroscopic and physicochemical behavior of magnesium phthalocyanine derivatives mono-substituted with a carboxylic acid group
- Authors: Nombona, Nolwazi , Chidawanyika, Wadzanai J U , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/244450 , vital:51258 , xlink:href="https://doi.org/10.1016/j.molstruc.2011.12.051"
- Description: This work reports on the synthesis of novel unsymmetrically substituted magnesium phthalocyanine complexes containing one carboxyl group. The physicochemical behavior of these complexes were compared with those of their unmetallated and zinc counterparts. The MgPcs showed interesting absorption spectra with [8,15,22-Tris-(naphtho)-4,5-(3-carboxy-1,2-dioxyphenyl)phthalocyaninato]magnesium (II) showing a large split in the Q band whereas [8,15,22-Tris-(naphtho)-2-(carboxy) phthalocyaninato]magnesium(II) presented only a small splitting. The magnesium phthalocyanine derivatives displayed higher fluorescence quantum yields compared to unmetallated and zinc phthalocyanine counterparts. The latter gave admirable triplet and singlet oxygen quantum yields. These molecules can distinctly be employed in the field of photodynamic therapy in combination with fluorescence imaging.
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- Date Issued: 2012
STAT3 interacts directly with Hsp90:
- Authors: Prinsloo, Earl , Kramer, Adam H , Edkins, Adrienne L , Blatch, Gregory L
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165142 , vital:41212 , DOI: 10.1002/iub.607
- Description: Heat shock protein 90 (Hsp90) functionally modulates signal transduction. The signal transducer and activator of transcription 3 (STAT3) mediates interleukin‐6 family cytokine signaling. Aberrant activation and mutation of STAT3 is associated with oncogenesis and immune disorders, respectively. Hsp90 and STAT3 have previously been shown to colocalize and coimmunoprecipitate in common complexes.
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- Date Issued: 2012
Students’ navigation of the uncharted territories of academic writing
- Authors: Bharuthram, Sharita , McKenna, Sioux
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187373 , vital:44626 , xlink:href="https://doi.org/10.1080/18146627.2012.742651"
- Description: Many students enter tertiary education unfamiliar with the ‘norms and conventions’ of their disciplines. Research into academic literacies has shown that in order to succeed in their studies, students are expected to conform to these norms and conventions, which are often unrecognized or seen as ‘common sense’ by lecturers. Students have to develop their own ‘map’ of their programme’s expectations in order to make sense of the seemingly mysterious practices they are expected to take on. This study, undertaken at a University of Technology in South Africa, details students’ perceptions of their writing difficulties and their attempts to navigate their way through various writing tasks. The findings reveal that students experience a range of difficulties and that the students often feel unsupported in their travails with academic writing.
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- Date Issued: 2012
Study South Africa
- Authors: International Education Association of South Africa (IEASA) , Jooste, Nico
- Date: 2012
- Subjects: Education, Higher -- South Africa , Universities and colleges -- South Africa , Technical Institutes -- South Africa , Vocational guidance -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/64928 , vital:28637 , ISBN 9780620542661
- Description: [Extract from article by Ms Merle Hodges]: A recent article points to the feeling of alienation that students feel when studying away from home. It seeks to address the problem by establishing a range of fora where foreign students can feel more ‘at home’. It encourages host students to be more willing to accommodate these ‘outsiders’ in order to boost the reputation of the institution. Most of these initiatives are slightly patronising, but obviously well-meant. The overriding sense behind the article is that international students, within higher education institutions, are a benevolent burden. International students should be looked after, because universities are generally maternal (they are someone’s alma mater after all), places of kindness (they literally give away knowledge) and generally care for others (community outreach is fundamental to most universities). More importantly, international students – in places like the USA and UK – generate additional funding in an environment where government and federal funding is drying up. But what if four out of every ten students in the world who graduated were from China and India? In the next eight years? That genial inconvenience now becomes an imperative. These are the predictions by such august organisations as The British Council and the education branch of the OECD. It is also anticipated that these countries will not be in a position to educate this number of students internally. Which, in turn, suggests that there will be mass outflows at the undergraduate level and, by sheer dint of numbers, also means that internationalisation is heading towards a compounding acceleration in numbers. Where then does internationalisation stand? It will no longer be an altruistic add-on, but core business to the lifeblood of the universities across the globe. As far back as 1994, Jane Knight understood internationalisation as a phenomenon that would have a profound impact on the functions and structures of the university. “Internationalization,” she points out, “is the process of integrating an international, intercultural, global outlook into the major functions of a university – teaching, SRC, and service functions.” Over the past year arguments have been made that suggest that global shifts in student demographics are not the ‘province’ of South African higher education and that our obligation is to focus internally, on poverty alleviation and job creation. This argument misses the point. The free flow of academics and students – especially the large number of postgraduate students from other countries already at our institutions – are working with our academics on solving exactly these kinds of problems. IEASA is no longer only about the 60 000 students who migrate to our shores annually. It’s about what they learn and the diverse experiences that they will go through; experiences that will change them for life and will inevitably bring them to a different understanding of the world that we, collectively, are presently fashioning. , 12th Edition
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- Date Issued: 2012
Submission to Press Freedom Commission (PFC) on Media Self-regulation, Co-regulation or Statutory regulation in South Africa:
- Authors: Wasserman, Herman , Steenveld, Lynette N , Strelitz, Larry N , Amner, Roderick J , Boshoff, Priscilla A , Mathurine, Jude , Garman, Anthea
- Date: 2012
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/143571 , vital:38263 , ISBN , https://www.ru.ac.za/media/rhodesuniversity/content/ruhome/documents/JMS Submission to Press Freedom Commission.pdf
- Description: Prof Duncan has outlined the relative merits and demerits of self-regulation, co-regulation and deregulation, with which we are in broad agreement. She has also ably dealt with the three functions of regulatory bodies, namely the setting of ground rules for the industry to ensure best practice; enforcement of these; and adjudication of claims and counter claims re journalistic practice (Duncan 2012, p17). Finally, she has also taken up the issue of the necessity of accepting Third Party Complaints as one of the fundamental mechanisms by which citizens can make complaints on the basis of principle, rather than being personally aggrieved. While we are in broad agreement with her on these issues, we would like to highlight some further points for consideration.
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- Date Issued: 2012
Substantive second-level reasoning and experiential learning in legal ethics
- Authors: Kruuse, Helen
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68983 , vital:29345 , https://hdl.handle.net/10520/EJC127082
- Description: Publisher version , This article takes a critical look at law teaching in South Africa and seeks to consider how the application of experiential learning theory may assist law students in gaining a deeper understanding of the law in general, and the complexities of real life practice in particular. While clinical legal education is often seen as the locus of experiential learning in law, the author proposes that well-structured simulations in class can achieve similar goals. The article comprises a description of the nature of experiential learning and a further description of the application of the principles of experiential learning in a particular simulation exercise in a Legal Ethics course (using the US case of Wash St Phys Ins Exch v Fisons Corp 858 P2d 1054 (Wash 1993) as a basis). The author posits that the so-called experiential learning "cycle" or "process" enables a process of learning which draws out the students' beliefs and ideas about a topic so that it can be examined, tested and integrated with new, more refined ideas. This notion is then in keeping with the expectation that students who emerge from higher education institutions have developed meta-cognitive skills. Essentially then, it is hoped that, by using the methods proposed in this article, students can then manage their own development and learning throughout life.
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- Date Issued: 2012
Suicide - a global overview and focus on the South African situation
- Authors: Alonso-Betancourt, O
- Date: 2012
- Subjects: Suicide and Epilepsy Suicide -- South Africa Suicide -- Assessment -- Prevention
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/11260/1067 , vital:30560
- Description: As a medical doctor you learn how to deal with death and you feel that your duty is to encourage people to fight against illness for their lives but, when you face suicide, you feel defenseless because it is the person him or herself who chooses to die. Another reason for choosing this topic is that I’m advocating the development and implementation of a Suicide Prevention Program in South Africa and this could be a good forum to talk about this important issue.
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- Date Issued: 2012
Syntheses, protonation constants and antimicrobial activity of 2-substituted N-alkylimidazole derivatives
- Authors: Kleyi, Phumelele , Walmsley, Ryan S , Gundhla, Isaac Z , Walmsley, Tara A , Jauka, Tembisa I , Dames, Joanna F , Walker, Roderick B , Torto, Nelson , Tshentu, Zenixole R
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184066 , vital:44165 , xlink:href="https://www.ajol.info/index.php/sajc/article/view/123858"
- Description: A series of N-alkylimidazole-2-carboxylic acid, N-alkylimidazole-2-carboxaldehyde and N-alkylimidazole-2-methanol derivatives [alkyl = benzyl, methyl, ethyl, propyl, butyl, heptyl, octyl and decyl] have been synthesized and the protonation constants determined. The antimicrobial properties of the compounds were tested against Gram-negative (Escherichi coli), Gram-positive (Staphylococcus aureus and Bacillus subtilis subsp. spizizenii) bacterial strains and yeast (C. albicans). Both the disk diffusion and broth microdilution methods for testing the antimicrobial activity showed that N-alkylation of imidazole with longer alkyl chains and the substitution with low pKa group at 2-position resulted in enhanced antimicrobial activity. Particularly, the N-alkylimidazole-2-carboxylic acids exhibited the best antimicrobial activity due to the low pKa of the carboxylic acid moiety. Generally, all the N-alkylimidazole derivatives were most active against the Gram-positive bacteria [S. aureus (MIC = 5–160 µg mL–1) and B. subtilis subsp. spizizenii (5–20 µg mL–1)], with the latter more susceptible. All the compounds showed poor antimicrobial activity against both Gram-negative (E. coli, MIC = 0.15 to >2500 µg mL–1) bacteria and all the compounds were inactive against the yeast (Candida albicans).
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- Date Issued: 2012
Synthesis and photophysical behavior of a novel zinc phthalocyanine containing a single carboxylic acid and three phenylthio substituents
- Authors: Forteath, Shaun , Antunes, Edith M , Chidawanyika, Wadzanai J U , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/243207 , vital:51127 , xlink:href="https://doi.org/10.1016/j.jlumin.2012.03.050"
- Description: Zinc 2, (3)-tri-(phenylthio)-2, (3)-carboxy phthalocyanine (ZnPc(COOH)(SPh)3), zinc 2, (3)-tetra-(phenylthio) phthalocyanine (ZnPc(SPh)4) and 2, (3)-tetra-(phenylthio) phthalocyanine (H2Pc(SPh)4) were synthesized and their photophysical behavior were compared with those of a number of zinc phthalocyanine (ZnPc) derivatives. ZnPc(COOH)(SPh)3 and ZnPc(SPh)4 had similar fluorescence (ΦF=0.14) and triplet state (ΦT=0.65) quantum yields in dimethylsulfoxide, hence showing no effects of the replacement of one of the phenylthio groups with a carboxylic acid group. ZnPc(COOH)(SPh)3 displayed a slightly shorter triplet lifetime (τT=331 μs) than ZnPc (τT=350 μs) in DMSO, but within the range of ZnPc derivatives. The triplet lifetime for ZnPc(COOH)(SPh)3 is much longer than for the symmetrical derivative (ZnPc(SPh)4) with τT=149 μs in DMSO.
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- Date Issued: 2012
Synthesis and photophysical properties of covalent conjugates of aqua platinum (II) and octacarboxy-substituted zinc phthalocyanine
- Authors: Bulgakov, Roman A , Kuznetsova, Nina A , Dolotova, Olga V , Solovieva, Ludmila I , Mack, John , Chidawanyika, Wadzanai J U , Kaliya, Oleg L , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/242726 , vital:51073 , xlink:href="https://doi.org/10.1142/S1088424612501209"
- Description: New covalent conjugates of aqua platinum(II) and octacarboxy-substituted zinc phthalocyanine, bearing one, two, three and four aqua platinum moieties on the periphery of the Pc ligand have been synthesized and characterized. The effect of the stepwise introduction of the aqua platinums on the photophysical and photochemical properties of these compounds has been investigated in dimethylsulfoxide solution. It has been found that aqua platinum moieties have only a limited effect on the dynamics of the singlet and triplet excited states, on the ability to sensitize singlet oxygen formation and on the photostability. Each conjugate has a high singlet oxygen quantum yield (ΦΔ 0.51–0.62) and thus retains potential for use as a dual action anticancer drugs by acting as a sensitizer for PDT in addition to the likely chemotherapeutic effects of the Pt(II) complexes.
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- Date Issued: 2012
Synthesis and photophysical properties of peripherally and non-peripherally mercaptopyridine substituted metal free, Mg (II) and Al (III) phthalocyanines
- Authors: Arslanoğlu, Yasin , Idowu, Mopelela , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/243248 , vital:51131 , xlink:href="https://doi.org/10.1016/j.saa.2012.04.004"
- Description: The syntheses and photophysical properties of metallophthalocyanines containing Mg2+ and Al3+ as central metal ions and their unmetallated derivative (complexes 3–8) tetra- substituted at the non-peripheral (α) and peripheral (β) positions with 2-mercaptopyridine are reported. The trends in triplet and fluorescence quantum yields are described for these compounds. The complexes exhibited relatively high triplet quantum yields (ΦT) ranging from 0.33 to 0.54 and fluorescence quantum yields (ΦF) ranging from 0.02 to 0.29. Triplet state lifetimes of the complexes were long ranging from 120 to 460 μs, indicating a potential use of these complexes as photosensitizers.
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- Date Issued: 2012
Synthesis and photophysicochemical properties of novel zinc phthalocyanines mono substituted with carboxyl containing functional groups
- Authors: Rapulenyane, Nomasonto , Antunes, Edith M , Masilela, Nkosiphile , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/242389 , vital:51037 , xlink:href="https://doi.org/10.1016/j.jphotochem.2012.09.007"
- Description: This work reports on the synthesis and the physicochemical properties of novel unsymmetrically substituted zinc phthalocyanines (complexes 8, 10 and 11) and their symmetrically substituted counterparts (complexes 9, 12 and 13). The new complexes and their counterparts were successfully structurally characterized by IR, NMR, mass spectral and elemental analyses. Low fluorescence quantum yields (0.032) and lifetimes (0.91 ns) were obtained for the symmetrical ZnOTPc (complex 9) compared to the higher fluorescence quantum yields (0.15, 0.13, 0.10, 0.09 and 0.29) and lifetimes (4.4, 1.69, 1.69, 2.16 and 3.23 ns) obtained for ZnMPCPc (8), ZnTDTPc (12), ZnMCapPc (10), ZnMCafPc (11) and ZnTCPPc (13), respectively. All the complexes showed the ability to produce singlet oxygen with the highest triplet quantum yields obtained for 8 and 10 (0.80 and 0.65 respectively). High triplet lifetimes (109–286 μs) were obtained for all complexes. Complex 8 showed the longest triplet and fluorescence lifetimes as well the largest triplet state and singlet oxygen quantum yields.
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- Date Issued: 2012
Synthesis and physicochemical behavior of new low symmetry Ge, Ti and Sn phthalocyanines
- Authors: Masilela, Nkosiphile , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/242421 , vital:51040 , xlink:href="https://doi.org/10.1016/j.synthmet.2012.07.028"
- Description: The synthesis and photophysicochemical properties of new low symmetrically Ge, Sn and Ti phthalocyanines substituted with one carboxy containing group are reported. Broading and splitting in the absorption spectra were observed for some of the complexes in particular for both the titanium Pcs due to loss of symmetry. Higher fluorescence quantum yields and lifetimes were obtained for the Pcs substituted with three benzyloxy (5–7) compared to their corresponding counterparts substituted with six 2-diethylaminoethylthiol groups (9–11). The germanium Pc complexes gave the highest triplet and singlet oxygen quantum yields compared to all the other complexes studied in DMF. All the complexes showed reasonable ability to generate singlet oxygen with quantum yields ranging from 0.54 to 0.69.
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- Date Issued: 2012
Synthesis and physicochemical behaviour of aluminium trikis and tetrakis (diaquaplatinum) octacarboxyphthalocynine
- Authors: Malinga, Nduduzo , Dolotova, Olga , Bulgakov, Roman , Antunes, Edith M , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/242687 , vital:51068 , xlink:href="https://doi.org/10.1016/j.dyepig.2012.05.011"
- Description: The combination of chemotherapy and photodynamic therapy was investigated by the synthesis and characterisation of phthalocyanine conjugates with Pt complexes. The complexes synthesized are: hydroxoaluminum trikis(diaquaplatinum) octacarboxyphthalocyanine (OHAlOCPc(Pt)3) and hydroxoaluminum tetrakis(diaquaplatinum) octacarboxyphthalocyanine (OHAlOCPc(Pt)4). The platinated phthalocyanine complexes gave long triplet lifetimes of 577 and 526 μs for OHAlOCPc(Pt)3 and OHAlOCPc(Pt)4, respectively. The triplet quantum yields were found to be 0.45 for OHAlOCPc(Pt)3 and 0.57 OHAlOCPc(Pt)4 while the singlet oxygen quantum yields were found to be 0.38 and 0.48, respectively.
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- Date Issued: 2012
Synthesis of phthalocyanine conjugates with gold nanoparticles and liposomes for photodynamic therapy
- Authors: Nombona, Nolwazi , Maduray, Kaminee , Antunes, Edith M , Karsten, Aletta , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/245798 , vital:51406 , xlink:href="https://doi.org/10.1016/j.jphotobiol.2011.11.007"
- Description: The efficiency of [2,9,17,23-tetrakis-(1,6-hexanedithiol)phthalocyaninato]zinc(II) as a photodynamic therapy (PDT) agent was investigated. This compound belongs to the second generation of photosensitizers currently tested for the cellular photo-damage of cancer cells. The production of reactive oxygen species (ROS) and phototoxicity of the photosensitizer were assessed. Healthy fibroblast cells and breast cancer (MCF-7) cells were treated with either free phthalocyanine or phthalocyanine bound to either gold nanoparticles or encapsulated in liposomes. Cell viability studies showed the optimum phototoxic effect on non-malignant cells to be 4.5 J cm−2. The PDT effect of the liposome bound phthalocyanine showed extensive damage of the breast cancer cells. Gold nanoparticles only showed a modest improvement in PDT activity.
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- Date Issued: 2012
Synthesis, density functional theory, molecular dynamics and electrochemical studies of 3-thiopheneacetic acid-capped gold nanoparticles
- Authors: Sosibo, Ndabenhle M , Mdluli, Phumlane S , Mashazi, Philani N , Dyan, Busiswa , Revaprasadu, Neerish , Nyokong, Tebello , Tshikhudo, Robert T , Skepu, Amanda , Van Der Lingen, Elma
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/246446 , vital:51477 , xlink:href="https://doi.org/10.1016/j.molstruc.2011.09.057"
- Description: Gold nanoparticles capped with a bifunctional ligand, 3-thiopheneacetic acid (3-TAA) were synthesised by borohydride reduction at room temperature. The transmission electron microscopy (TEM) analysis showed that the particle aggregates and had semi-linear partial linkages that could be attributed to multi-modal binding of the ligand with various gold nanoparticles through the terminal thiolether (–S–) group and oxygen of the carboxylic (–COOH) group. This bimodal interaction led to limited stability of the resultant nanoparticles when tested using highly electrolytic media. To investigate further, density functional theory (DFT) quantum chemical and molecular dynamic calculations were conducted. The energetically favorable binding modes of the ligand to gold nanoparticle surfaces using the Gaussian program were studied. The DFT results showed kinetic stability of Au–3-TAA–Au interactions leading to inter-particle coupling or aggregation. Electrochemical analysis of the resultant nature of the capping agent revealed that 3-thiopheneacetic acid did not form a polymer during the preparation of Au–3-TAA. The cyclic voltammograms of Au–3-TAA nanoparticles coated glassy carbon electrode showed a typical gold character with the oxidation and reduction peaks at 1.4 V and 0.9 V, respectively.
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- Date Issued: 2012