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Improving access to evidence-based interventions for trauma-exposed adults in low-and middle-income countries

  • Authors: Kaminer, Debra , Booysen, Duane D , Ellis, Kate , Kristensen, Christian H , Patel, Anushka R , Robjant, Katy , Sardana, Srishti
  • Date: 2024
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/454095 , vital:75309 , xlink:href="https://doi.org/10.1002/jts.23031"
  • Description: In low- and middle-income countries (LMICs), the mental health consequences of trauma exposure pose a substantial personal, societal, and economic burden. Yet, the significant need for evidence-based mental health treatment remains largely unmet. To unlock the potential for mental health care for trauma survivors in lower-resource contexts, it is critical to map treatment barriers and identify strategies to improve access to evidence-based, culturally appropriate, and scalable interventions. This review, based on an International Society for Traumatic Stress (ISTSS) briefing paper, describes the treatment gap facing adults with traumatic stress in LMICs and identifies the barriers that contribute to this gap. We then highlight strategies for enhancing access to effective treatments for these populations, including task-sharing, the use of culturally adapted and multiproblem interventions, and digital tools to scale access to appropriate care. Finally, we offer recommendations for policymakers, researchers, and service providers to guide an agenda for action to close the treatment gap for trauma survivors in LMICs.
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  • Date Issued: 2024

Teaching comprehensive sexuality education in a traumatized society: recognizing teachers as sexual, reproductive, and mental health frontline workers

  • Authors: Macleod, Catriona I , du Plesis, Ulandi
  • Date: 2024
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/441316 , vital:73876 , xlink:href=" https://doi.org/10.3389/feduc.2024.1276299"
  • Description: Research on school-based sexuality education in South Africa, taught within Life Orientation (LO), has mainly focused on learners’ responses, how teachers approach the subject, and the curriculum content. Critiques have included heteronormative biases, an emphasis on danger, disease and damage, a reinforcement of gendered binaries, and the lack of pleasure or well-being discourses. In contrast, our research focused on the unexpected moments teachers experience, i.e., the ethical, emotional or psychological challenges they encounter in their interactions with learners.
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  • Date Issued: 2024

A Practical Use for AI-Generated Images

  • Authors: Boby, Alden , Brown, Dane L , Connan, James
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/463345 , vital:76401 , xlink:href="https://link.springer.com/chapter/10.1007/978-3-031-43838-7_12"
  • Description: Collecting data for research can be costly and time-consuming, and available methods to speed up the process are limited. This research paper compares real data and AI-generated images for training an object detection model. The study aimed to assess how the utilisation of AI-generated images influences the performance of an object detection model. The study used a popular object detection model, YOLO, and trained it on a dataset with real car images as well as a synthetic dataset generated with a state-of-the-art diffusion model. The results showed that while the model trained on real data performed better on real-world images, the model trained on AI-generated images, in some cases, showed improved performance on certain images and was good enough to function as a licence plate detector on its own. The study highlights the potential of using AI-generated images for data augmentation in object detection models and sheds light on the trade-off between real and synthetic data in the training process. The findings of this study can inform future research in object detection and help practitioners make informed decisions when choosing between real and synthetic data for training object detection models.
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  • Date Issued: 2023

Evaluation of the antibacterial activity of gallic acid anchored phthalocyanine-doped silica nanoparticles towards Escherichia coli and Staphylococcus aureus biofilms and planktonic cells

  • Authors: Magadla, Aviwe , Openda, Yolande Ikala , Mpeta, Lekhetho S , Nyokong, Tebello
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/360424 , vital:65087 , xlink:href="https://doi.org/10.1016/j.pdpdt.2023.103520"
  • Description: In this work, we have described the synthesis of phthalocyanine complexes Zn(II) tetrakis 4-(5-formylpyridin-2-yl)oxy) phthalocyanine (2), Zn(II) tetrakis-1 butyl 4-(2-(6- (tetra-phenoxy)pyridin-3-yl) vinyl)pyridin-1-ium phthalocyanine (3) and Zn(II) tetrakis 1 butyl 5-(2-(1-butylpyridin-1-ium-4-yl)vinyl)-2-(tetra-phenoxy)pyridin-1-ium phthalocyanine (4). The effect of a varying number of charges when the Pc complexes are alone or grafted in gallic acid (GA) tagged silica nanoparticles on photodynamic antimicrobial chemotherapy (PACT) is investigated toward Staphylococcus aureus (S.aureus) and Escherichia coli (E.coli) in both planktonic and biofilm forms. Complex 4, bearing a total of 8 cationic charges, displayed the highest activity with log CFU (colony forming units) values of 8.60 and 6.42 against E.coli and S.aureus biofilms, respectively. The surface stability of E.coli and S.aureus biofilms in the presence of 4 and its conjugate was analyzed using cyclic voltammetry. Scanning electron microscopy (SEM) and Raman spectra are also used to study the conformational and biochemical changes within biofilm upon subjecting them to PACT.
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  • Date Issued: 2023

Inhibiting human dipeptidyl peptidase IV using cannabinoids and Leonotis leonurus extracts as a potential therapy for the management of diabetes

  • Authors: Mkabayi, Lithalethu , Viljoen, Zenobia , Lobb, Kevin A , Pletschke, Brett I , Frost, Carminita L
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/452745 , vital:75167 , xlink:href="https://www.thieme-connect.com/products/ejournals/html/10.1055/s-0043-1773924"
  • Description: Diabetes is a chronic metabolic disorder that has been shown to affect a growing number of people worldwide. Controlling blood glucose levels is one of the possible strategies to treat type 2 diabetes mellitus (T2DM). It has been established that the inhibition of dipeptidyl peptidase IV (DPP-IV) prolongs the activity of incretin hormones, which serve as key stimulators of insulin secretion and regulation of blood glucose levels. Although several synthetic DPP-IV inhibitors are available, there is still a need for naturally sourced inhibitors that have fewer to no undesirable side effects. In this study, cannabinoids and Leonotis leonurus aqueous extracts were evaluated for their inhibitory effects against recombinant human DPP-IV. Their potential inhibition mechanism was explored using in vitro and in silico approaches. All tested cannabinoids and L. leonurus aqueous extracts showed significant inhibitory activity against DPP-IV. Phytochemical analysis of L. leonurus extract indicated the presence of diterpenoids and alkaloids, which might contribute to the inhibitory activity. In molecular docking studies, among different constituents known in L. leonurus, luteolin and marrubiin showed binding energy of -7.2 kcal/mol and cannabinoids (cannabidiol, cannabigerol, cannabinol and Δ9-tetrahydrocannabinol) showed binding energies ranging from -6.5 to -8.2 kcal/mol. Molecular dynamics revealed that all tested compounds formed stable complexes with the enzyme during 100 ns simulation, indicating that they are good ligands. This study provided preliminary evidence for the potential application of the selected cannabinoids and L. leonurus in maintaining glucose homeostasis, suggesting that they could be suitable therapeutic candidates for managing T2DM.
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  • Date Issued: 2023

International agreement for the use and exchange of classical biological control genetic resources: a practical proposal

  • Authors: Mason, Peter G , Mc Kay, Fernando , Silvestri, Luciano C , Hill, Martin P , Weyl, Philip S R , Hinz, Hariet L , Brodeur, Jacques , Vitorino, Marcello Diniz , Barratt, Barbara I P
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/418025 , vital:71502 , xlink:href="https://doi.org/10.1007/s10526-023-10177-7"
  • Description: The Nagoya Protocol on Access and Benefit Sharing (ABS) was implemented to further develop the third objective of the Convention on Biological Diversity, the fair and equitable sharing of benefits arising out of the utilization of genetic resources. Interpretation of this agreement is wide-ranging and there is concern that if ABS measures are poorly implemented biological control and the resultant public good will be greatly impeded. The ethos of multilateral use and exchange of genetic resources used in classical biological control will be particularly affected. In the spirit of the fair and equitable sharing of benefits arising out of the utilization of genetic resources, we propose a simple practical solution in the form of an international agreement on the use and exchange of classical biological control genetic resources.
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  • Date Issued: 2023

Know thy enemy: Investigating genetic contributions from putative parents of invasive Nymphaea mexicana hybrids in South Africa as part of efforts to develop biological control

  • Authors: Reid, Megan K , Paterson, Iain D , Coetzee, Julie A , Gettys, Lyn A , Hill, Martin P
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/423540 , vital:72070 , xlink:href="https://doi.org/10.1016/j.biocontrol.2023.105291"
  • Description: Hybridisation of alien invasive plants complicates efforts to develop biological control, because variations in the genetic makeup of the target plant can impact the survival of host specific agents that have evolved adaptations specific to the original host. To maximise the likelihood of success in a biological control program, potential agents should therefore be collected from populations in the region of origin that are genetically similar to plants in the invaded range. Molecular markers are useful tools to understand genetic contributions in hybrid populations, especially where morphological differentiation is difficult. Nymphaea mexicana Zuccarini (Nymphaeaceae) is an invasive alien plant in South Africa that is being targeted for biological control, but hybrids with intermediate morphological traits are also present at several sites. In this study, ISSR (inter simple sequence repeats) and ITS (internal transcribed spacer) markers were used to determine which Nymphaea species are likely to be putative parents of these hybrids, and morphological characters were also investigated to determine if genetic and morphological traits matched. Two major hybrid groups were identified, with one group clustering with Nymphaea odorata Aiton and the other clustering with Nymphaea alba L. A third, smaller group clustered with Nymphaea tetragona Georgi, whereas the remaining samples clustered with pure N. mexicana from the native range. Morphological features agreed with deductions drawn from molecular data. These results allow us to focus efforts to find compatible biological control agents and better understand the complicated genetic structure of N. mexicana and Nymphaea hybrids in South Africa.
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  • Date Issued: 2023

Learning Movement Patterns for Improving the Skills of Beginner Level Players in Competitive MOBAs

  • Authors: Brown, Dane L , Bischof, Jonah
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/464161 , vital:76482 , xlink:href="https://link.springer.com/chapter/10.1007/978-981-99-1624-5_45"
  • Description: League of Legends is a massively multiplayer online battle arena (MOBA)—a form of online competitive game in which teams of five players battle to demolish the opponent’s base. Expert players are aware of when to target, how to maximise their gold, and how to make choices. These are some of the talents that distinguish them from novices. The Riot API enables the retrieval of current League of Legends game data. This data is used to construct machine learning models that can benefit amateur players. Kills and goals can assist seasoned players understand how to take advantage of micro- and macro-teams. By understanding how professional players differ from novices, we may build tools to assist novices’ decision-making. 19 of 20 games for training a random forest (RF) and decision tree (DT) regressor produced encouraging results. An unseen game was utilised to evaluate the impartiality of the findings. RF and DT correctly predicted the locations of all game events in Experiment 1 with MSEs of 9.5 and 10.6. The purpose of the previous experiment was to fine-tune when novice players deviate from professional player behaviour and establish a solid commencement for battles. Based on this discrepancy, the system provided the player with reliable recommendations on which quadrant they should be in and which event/objective they should complete. This has shown to be a beneficial method for modelling player behaviour in future research.
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  • Date Issued: 2023

Puma (Puma concolor) sex influences diet in southwest New Mexico

  • Authors: Bernard, Kelly M T , Perry, Travis W , Mgqatsa, Nokubonga
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/462647 , vital:76322 , xlink:href="https://doi.org/10.3398/064.083.0201"
  • Description: Puma (Puma concolor) is a wide-ranging, large felid species, and site-specific research on its diet is important for local management. Like the diets of other large felids, puma diets may differ between sex due to size dimorphism and between seasons due to changes in prey vulnerability and availability. We investigated the influence of sex and season on puma diet in southwest New Mexico in terms of prey species and size categories. Pumas (10 males, 6 females) were tracked with GPS collars for an average of one year per individual between February 2008 and July 2020. Puma location was recorded every 2 hours between 19:00 and 7:00, and kill sites were identified by a minimum of 2 GPS fixes occurring within 100 m and 100 hours of the first fix. Pumas specialized on mule deer (Odocoileus hemionus) and elk (Cervus elaphus) but also preyed upon a range of other species of different sizes. The probability of making a medium-sized kill such as a mule deer was higher for females than for males, while the probability of making an extra-large kill, such as an elk, was considerably greater for males than for females. There was substantial variation in prey species and size categories killed by individual pumas, particularly of smaller-sized prey like collared peccary (Pecari tajacu) and skunks (e.g., Spilogale gracilis, Mephitis mephitis). Our findings concur with previous research on the importance of mule deer and elk in puma diet, demonstrate individual variation in prey killed, and may have management implications.
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  • Date Issued: 2023

Signposts on the road toward transformative governance: how a stronger focus on diverse values can enhance environmental policies

  • Authors: Keleman, Eszter , Subramanian, Suneetha M , de Vos, Alta , Amaruzaman, Sacha , Porter-Bolland, Luciana , Islar, Mine , Kosmus, Marina , Nakangu, Barbara , Nuesiri, Emmanuel , Robles, Gabriela A , Yiu, Evonne , Emerton, Lucy , Zólyomi, Ágnes
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/415927 , vital:71301 , xlink:href="https://doi.org/10.1016/j.cosust.2023.101351"
  • Description: Transformative change toward sustainability is increasingly recognized as inevitable to avoid the collapse of socioecological systems. However, for a deep and system-wide transformation, governance approaches and policymaking need to be changed too. This paper discusses how a diverse value approach in environmental policymaking could be undertaken to foster transformative governance that can further lead to system-wide transitions. Based on the analysis of different policy options’ transformative potential, we argue that the more diverse values addressed by a policy instrument, the bigger its transformative potential. Weaving values into policy decision-making is possible at several junctures of the policy process, but context-specificities should always be considered, and capacities must be enhanced at all levels, both for public and private actors.
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  • Date Issued: 2023

The in-vitro proliferation-suppression of MCF-7 and HeLa cell lines mediated by differently substituted ionic phthalocyanines in sonodynamic therapy supplemented-photodynamic therapy

  • Authors: Nene, Lindokuhle Cindy , Nyokong, Tebello
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/360461 , vital:65090 , xlink:href="https://doi.org/10.1016/j.jinorgbio.2022.112084"
  • Description: This work focuses on the study of the effects of the ultrasonic frequency (MHz) and power (W.cm−2) on the stability, reactive oxygen species yields and cytotoxicity activities of differently substituted ionic phthalocyanines (Pcs) in sonodynamic therapy (SDT). Four ultrasonic parameters were investigated: Par I (1 MHz: 1 W.cm−2), Par II (1 MHz: 2 W.cm−2), Par III (3 MHz: 1 W.cm−2) and Par IV (3 MHz: 2 W.cm−2). A higher degradation of the Pcs was observed with increasing power at the Par II. Two reactive oxygen species (ROS) were detected in the ultrasound treated Pcs: singlet oxygen and hydroxyl radicals. Due to minimal degradation of most Pcs, Par I was chosen for SDT, photodynamic therapy (PDT), and photo-sonodynamic therapy (PSDT) against Michigan Cancer Foundation-7 and Henrietta Lacks cancer cell lines. PSDT generally showed improved therapeutic efficacies of the Pcs compared to the SDT and PDT mono treatments.
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  • Date Issued: 2023

The Southern African Program on Ecosystem Change and Society: an emergent community of practice

Application of gold and palladium nanoparticles supported on polymelamine microspheres in the oxidation of 1-phenylethanol and some other phenyl substituted alcohols

  • Authors: Storm, Ené , Maggott, Emile D , Mashazi, Philani N , Nyokong, Tebello , Malgas-Enus, Rehana , Mapolie, Selwyn F
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/299824 , vital:57858 , xlink:href="https://doi.org/10.1016/j.mcat.2022.112456"
  • Description: Melamine formaldehyde and melamine resorcinol formaldehyde microspheres were decorated with Au and Pd nanoparticles and applied as heterogeneous catalysts in the oxidation of 1-phenylethanol. The catalysts showed similar activities irrespective of the support employed. Moderate conversion activities of 48–50% were achieved when using acetonitrile as solvent; however, when employing water as solvent, the supported catalysts formed a three-phase, emulsion system which facilitated the catalytic conversion of 1-phenylethanol to acetophenone at much higher conversions of around 83%. The oxidant, TBHP, decomposed rapidly in acetonitrile, whilst it remained stable in aqueous solution, leading to the enhanced activities observed when using water as solvent. These systems also proved to be recyclable for up to five cycles, with only slight loss of activity observed; this can be attributed to the physical loss of catalyst during the workup procedure conducted between each cycle.
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  • Date Issued: 2022

Design and fabrication of electrochemical sensor based on molecularly imprinted polymer loaded onto silver nanoparticles for the detection of 17-β-Estradiol

  • Authors: Regasa, Melkamu Biyana , Nyokong, Tebello
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/300287 , vital:57913 , xlink:href="https://doi.org/10.1002/jmr.2978"
  • Description: In this research report, we prepared an electrochemical sensor based on the molecularly imprinted poly(p-aminophenol) supported by silver nanoparticles capped with 2-mercaptobenzoxazole for the selective and sensitive detection of endocrine disrupting 17-β-estradiol (E2). The electropolymerization of the functional monomer prepared the proposed molecularly imprinted polymer (MIP) composite-based sensor in the presence of E2 as a template. The recognition materials were characterized using Fourier transform infrared, cyclic voltammetry (CV), square wave voltammetry (SWV), scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray powder diffraction techniques. The electrochemical measurements were performed by employing both CV and SWV methods. We did the optimization of critical parameters affecting the sensor performances through the experimental design and verification. The developed sensor showed a linear range from 10 pM to 100 nM with the calculated quantification and detection limits of 1.86 and 6.19 pM, respectively. The incorporation of AgNP with high electrical conductivity into the MIP matrix enhanced the sensor's performance. Furthermore, the sensor was applied to determine E2 in real water samples without any sample preconcentration steps to achieve the percent recovery of 91.87% to 98.36% and acceptable reusability and storage stability performances.
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  • Date Issued: 2022

Integrated photocatalyst adsorbents based on porphyrin anchored to activated carbon granules for water treatment

  • Authors: Oyim, James , Amuhaya, Edith K , Matshitse, Refilwe , Mack, John , Nyokong, Tebello
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/300101 , vital:57893 , xlink:href="https://doi.org/10.1016/j.cartre.2022.100191"
  • Description: Integration of adsorption and photocatalysis processes can lead to several benefits in water treatment. Integrating well-known adsorbents with photocatalysts ensures that all the interesting components are preserved and helps to overcome the serious downsides of each material and technique when operated independently. In this work, we introduce a new concept of combining both absorption and photodegradation mechanisms using organic photocatalytic adsorbents for water purification. This was achieved by formulating photosensitizing hybrids based on a newly synthesized chloroindium (III) 5,10,15,20-tetrakis(4-acetamidophenyl) porphyrin (InTAAP) compound, anchored on oxygen functionalized coconut shell-based activated carbon granules supports. The fashioned integrated photocatalyst adsorbent hybrid (InTAAP(ACO)) was then studied for their adsorption and photodegradation efficiency using methylene blue dye, where InTAAP(ACO) showed excellent photocatalytic activity compared to ACO and unfunctionalized activated carbon granules (AC), with appreciably high and adsorption properties as AC and ACO.
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  • Date Issued: 2022

Landscape drivers of mammal habitat use and richness in a protected area and its surrounding agricultural lands

  • Authors: Bellón, Beatriz , Henry, Dominic AW , Renaud, Pierre-Cyril , Roque, Fabio de O , Santos, Cyntia Cavalcante , Melo, Isabel , Arvor, Damien , de Vos, Alta
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/415873 , vital:71296 , xlink:href="https://doi.org/10.1016/j.agee.2022.107989"
  • Description: Protected areas (PAs) are key to conserving biodiversity and ecosystem services globally, but their effectiveness increasingly depends on the ability of the surrounding agricultural areas to support biodiversity and secure connectivity at the landscape level. This requires monitoring the broader multi-use landscapes in which PAs exist and identifying the landscape characteristics that support rich, functional wildlife communities. Here, we investigated the species richness and habitat use patterns of a mammal community in relation to different landscape variables and land use and land cover (LULC) types in a PA and its surrounding agricultural lands in the Cerrado. We first used a hierarchical multi-species occupancy model with input camera trap data and eight landscape variables (vegetation productivity, phenology, and heterogeneity, distance to water, roads and settlements, and the PA, slope, and elevation) to estimate the species richness and habitat use of 29 mammal species across the landscape. We then analyzed the relationships between the species richness and habitat use and the landscape variables at the site level, as well as the distribution of species at the landscape level in relation to the different natural and agricultural LULC types.
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  • Date Issued: 2022

Measuring discrimination experienced by people with a mental illness

  • Authors: Brohan, Elaine , Thornicroft, Graham , Rüsch, Nicolas , Lasalvia, Antonio , Campbell, Megan M , Yalçınkaya-Alkar, Özden , Lanfredi, Mariangela , Ochoa, Susana , Üçok, Alp , Tomás, Catarina , Fadipe, Babatunde , Sebes, Julia , Fiorillo, Andrea , Sampogna, Gaia , Paula, Cristiane Silvestre , Valverde, Leonadis , Schomerus, Georg , Klemm, Pia , Ouali, Uta , Castelein, Stynke , Alexová, Aneta , Oexle, Nathalie , Guimarães, Patrícia Neves , Sportel, Bouwina Esther , Chang, Chih-Cheng , Li, Jie , Shanthi, Chilasagaram , Reneses, Blanca , Bakolis, Ioannis , Evans-Lacko, Sarah
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/302498 , vital:58202 , xlink:href="https://doi.org/10.1017/S0033291722000630"
  • Description: Background: The Discrimination and Stigma Scale (DISC) is a patient-reported outcome measure which assesses experiences of discrimination among persons with a mental illness globally. Methods: This study evaluated whether the psychometric properties of a short-form version, DISC-Ultra Short (DISCUS) (11-item), could be replicated in a sample of people with a wide range of mental disorders from 21 sites in 15 countries/territories, across six global regions. The frequency of experienced discrimination was reported. Scaling assumptions (confirmatory factor analysis, inter-item and item-total correlations), reliability (internal consistency) and validity (convergent validity, known groups method) were investigated in each region, and by diagnosis group. Results: 1195 people participated. The most frequently reported experiences of discrimination were being shunned or avoided at work (48.7%) and discrimination in making or keeping friends (47.2%). Confirmatory factor analysis supported a unidimensional model across all six regions and five diagnosis groups. Convergent validity was confirmed in the total sample and within all regions [ Internalised Stigma of Mental Illness (ISMI-10): 0.28–0.67, stopping self: 0.54–0.72, stigma consciousness: −0.32–0.57], as was internal consistency reliability (α = 0.74–0.84). Known groups validity was established in the global sample with levels of experienced discrimination significantly higher for those experiencing higher depression [Patient Health Questionnaire (PHQ)-2: p more than 0.001], lower mental wellbeing [Warwick-Edinburgh Well-being Scale (WEMWBS): p is less than 0.001], higher suicidal ideation [Beck Hopelessness Scale (BHS)-4: p is less than 0.001] and higher risk of suicidal behaviour [Suicidal Ideation Attributes Scale (SIDAS): p is less than 0.001]. Conclusions: The DISCUS is a reliable and valid unidimensional measure of experienced discrimination for use in global settings with similar properties to the longer DISC. It offers a brief assessment of experienced discrimination for use in clinical and research settings.
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  • Date Issued: 2022

Photo-and thermoresponsive N-salicylideneaniline derivatives: solid-state studies and structural aspects

  • Authors: Hulushe, Siyabonga T , Malan, Frederick P , Hosten, Eric C , Lobb, Kevin A , Khanye, Setshaba D , Watkins, Gareth M
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/451137 , vital:75021 , xlink:href="https://pubs.rsc.org/en/content/articlehtml/2022/nj/d1nj03056f"
  • Description: N-Salicylideneaniline (SA) and its derivatives are known to possess chromism upon exposure to external stimuli. Herein, we present mechanochemical synthesis of a series of photo-and thermoresponsive SAderivatives and report on solid-state stabilisation of their tautomeric forms either by change in temperature or by photoirradiation. The influence of UV light on proton transfer between the enol-imine (EI) and keto-amine (KA) forms was investigated at l1 = 254 and l2 = 365 nm. Differential scanning calorimetry (DSC) measurements provided extra information on the thermodynamic relationship between the prototropic tautomers, and their exposition to liquid nitrogen, combined with variable temperature single-crystal X-ray diffraction (VT-SCXRD) and spectroscopic data, ascertained structural reasons for the intrinsic thermo-optical properties of the compounds. A series of structural determinations between 150 and 300 K further shed light on the thermomechanical behaviour exhibited by the thermoresponsive compounds. By virtue of calorimetry we were able to demonstrate proton transfer via the intramolecular ON hydrogen bond over the temperature range 193–453 K. This present work demonstrates the importance of applying complementary analytical techniques and appropriate approaches for understanding the switching behaviour between the EI and KA forms. Furthermore, the assertion that it is predominantly the planarity (j o 251) that determines thermochromaticity is questioned.
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  • Date Issued: 2022

Photodynamic activity of novel cationic porphyrins conjugated to graphene quantum dots against Staphylococcus aureus

  • Authors: Magaela, N Bridged , Makola, Lekgowa C , Managa, Muthumuni , Nyokong, Tebello
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/295797 , vital:57379 , xlink:href="https://doi.org/10.1142/S1088424622500316"
  • Description: Novel 5-(pyridyl)-10-15-20-tris(4-bromophenyl) porphyrin (complex 1), indium metal derivative (complex 2), and quaternized derivative (complex 3) were synthesized and conjugated to graphene quantum dots (GQDs). The conjugation of the porphyrins to GQDs was through ππ-ππ stacking. Herein, the ππ-ππ stacking approach was used to avoid covalent conjugation which might compromise the intrinsic chemical and physical properties. The photodynamic activities of the proposed nanomaterials were assessed towards Staphylococcus aureus cell obliteration. The photophysical properties of the prepared complexes were also studied prior to the application. Moreover, a decrease in fluorescence lifetimes was observed upon metalation of complex 1. As anticipated, singlet oxygen quantum yield (ΦΔ)ΦΔ) increased notably upon heavy metal (indium) insertion and upon composite formation. Antimicrobial photodynamic therapy comparative studies were done on quaternized and unquaternized indium porphyrins conjugated to GQDs. Complex 3-GQDs exhibited the highest antibacterial activities compared to other complexes, and this was attributed to the high ΦΔΦΔ which plays an imperative role in photodynamic therapy applications.
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  • Date Issued: 2022

Photodynamic therapy characteristics of phthalocyanines in the presence of boron doped detonation nanodiamonds

  • Authors: Matshitse, Refilwe , Nwaji, Njemuwa , Managa, Muthimuni , Chen, Zhi-Long , Nyokong, Tebello
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/229921 , vital:49723 , xlink:href="https://doi.org/10.1016/j.pdpdt.2021.102705"
  • Description: The synthesis, photophysicochemical and photodynamic therapy (PDT) activities of benzothiazole substituted zinc phthalocyanine (Pc): 1 (asymmetrically substituted and composed of no charges), 2 (asymmetrically substituted and composed of three positive charges), and 3 (symmetrically substituted and composed of four positive charges), are presented. The triplet and singlet oxygen quantum yields were highest for complex 2 showing the importance of asymmetry and charge. The complexes are covalently and non-covalently linked to B doped detonation nanodiamonds (B@DNDs) to yield nanohybrids (B@DNDs-1, B@DNDs-2, B@DNDs-3). The presence of B@DNDs, asymmetry and positive charge resulted in improved PDT with the lowest cell viability being observed for B@DNDs-2 at 5%. The cell viability ranged from 5% to 7% for the nanohybrids compared to 19–26% for Pcs alone.
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  • Date Issued: 2022
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