25 research outputs found

    The perspectives of users of antiretroviral therapy on structural barriers to adherence in South Africa

    Get PDF
    Background: The effectiveness of antiretroviral therapy (ART) and the importance of adherence to treatment regimens are widely known. Yet, suboptimal adherence to ART and retention in care of patients still persists and, by many accounts, is fairly widespread. The aim of this study was to identify the structural barriers that influenced adherence among patients who were enrolled in the national ART programme in South Africa.Method: In this qualitative study, semi-structured interviews were conducted with a sample of 10 patients receiving ART at a public hospital in South Africa.Results: The results of the interviews were categorised according to poverty-related, institution-related and social barriers to clinic attendance and pill-taking, which collectively formed the structural barriers to adherence. The chief structural barriers to clinic attendance were time away from work, transport expenses, long waiting times and negative experiences with clinic staff. The chief barriers to pill-taking were food insecurity, stigma and discrimination.Conclusion: The barriers to adherence are discussed. Attention is called to the extraindividual factors that influenced ART adherence. We conclude that contextual factors, such as a healthcare-enabling environment, might play an important role in influencing healthcare-promoting behaviour among patients

    Progress and Perspectives Beyond Traditional RAFT Polymerization.

    Full text link
    The development of advanced materials based on well-defined polymeric architectures is proving to be a highly prosperous research direction across both industry and academia. Controlled radical polymerization techniques are receiving unprecedented attention, with reversible-deactivation chain growth procedures now routinely leveraged to prepare exquisitely precise polymer products. Reversible addition-fragmentation chain transfer (RAFT) polymerization is a powerful protocol within this domain, where the unique chemistry of thiocarbonylthio (TCT) compounds can be harnessed to control radical chain growth of vinyl polymers. With the intense recent focus on RAFT, new strategies for initiation and external control have emerged that are paving the way for preparing well-defined polymers for demanding applications. In this work, the cutting-edge innovations in RAFT that are opening up this technique to a broader suite of materials researchers are explored. Emerging strategies for activating TCTs are surveyed, which are providing access into traditionally challenging environments for reversible-deactivation radical polymerization. The latest advances and future perspectives in applying RAFT-derived polymers are also shared, with the goal to convey the rich potential of RAFT for an ever-expanding range of high-performance applications

    Use of a point-of-care progesterone assay to predict onset of parturition in the bitch

    Get PDF
    An assay of circulating progesterone (P4) is commonly used to estimate progress through late gestation in the bitch. Point-of-care assays provide rapid results, a major advantage over laboratory-based assays. This study aims to compare P4 levels determined by the Catalyst® Progesterone point-of-care assay with those determined by chemiluminescent immunoassay (CLIA) and to identify the expected distribution of Catalyst P4 levels at time intervals 3 days prior to the onset of parturition in pregnant bitches. Twenty-eight pregnant bitches carrying two or more fetuses were admitted to a specialist veterinary reproduction hospital 53 days after the onset of cytological diestrus or, when that date was not known, 57 days after the last mating. Vaginal speculum examinations were performed every 6 h until the onset of cervical dilatation (TCD). Serum samples were collected twice daily (08h00 and 18h00) until TCD. For most samples, fresh serum was assayed for P4 immediately using the Catalyst assay (CatP4), then frozen until assayed by CLIA (IMMULITE 2000; ImmP4). However, for some samples, CatP4 was not analyzed prior to freezing. For these data points (n = 33), CatP4 for fresh serum was estimated from CatP4 assayed on frozen-thawed serum, based on a comparison between CatP4 on fresh vs. frozen-thawed sera. In comparison to ImmP4, CatP4 levels up to and including 7 nmol/L appear to have a constant bias of −1.69 nmol/L (limits of agreement −4.91 to 1.52), while levels >7 nmol/L appear to have a proportional bias of −17.9% (limits of agreement −68.6% to 32.7%). Bootstrapped percentiles of CatP4 results spanned 0.4– 9 nmol/L within 12 h of TCD, 0.9–11 nmol/L 12–24 h from TCD, and 2.2–13.5 nmol/L 24–36 h from TCD. A CatP4 >9 nmol/L indicates a bitch that is unlikely to reach TCD within 12 h. Bitches with CatP4s below 3.5 nmol/L are likely to reach TCD within 36 h and bitches with a CatP4 below 2.2 nmol/L are likely to reach TCD within 24 h. In conclusion, the Catalyst Progesterone assay provides rapid assessment of circulating P4 in the bitch, with clinical application in the monitoring of late term pregnant bitches.The National Research Foundation of South Africahttps://www.frontiersin.org/journals/veterinary-sciencedm2022Production Animal Studie

    High-throughput CO<inf>2</inf> capture using PIM-1@MOF based thin film composite membranes

    Full text link
    © 2020 Elsevier B.V. Carbon capture from power plants represents a powerful technique to mitigate increasing greenhouse gas emissions. In this work, we describe a thin film composite (TFC) membrane incorporating a polymer of intrinsic microporosity (PIM-1) and metal organic framework (MOF) nanoparticles for post-combustion CO2 capture. The novel TFC membrane design consists of three layers: (1) a CO2 selective layer composed of a PIM-1@MOF mixed matrix; (2) an ultrapermeable PDMS gutter layer doped with MOF nanosheets; and (3) a porous polymeric substrate. Notably, the PDMS@MOF gutter layer incorporating amorphous nanosheets provides a CO2 permeance of 10,000–11,000 GPU, suggesting less gas transport resistance in comparison with pristine PDMS gutter layers. In addition, by blending nanosized MOF particles (MOF-74-Ni and NH2-UiO-66) into PIM-1 to afford a selective layer, the resultant TFC membrane assembly delivered improved CO2 permeance of 4660–7460 GPU and CO2/N2 selectivity of 26–33, compared with a pristine PIM-1 counterpart (CO2 permeance of 4320 GPU and CO2/N2 selectivity of 19). Furthermore, PIM-1@MOF based TFC membranes displayed an enhanced resistance to aging effect, maintaining a stable CO2 permeance of 900–1200 GPU and CO2/N2 selectivity of 26–30 after aging for 8 weeks. To the best of our knowledge, the high CO2 separation performance presented here is unprecedented for PIM-1 based TFC membranes reported in the open literature

    Trauma exposure, posttraumatic stress disorder and the effect of explanatory variables in paramedic trainees

    Get PDF
    Fjeldheim, C. B. et al. Trauma exposure, posttraumatic stress disorder and the effect of explanatory variables in paramedic trainees. BMC Emergency Medicine, 14(1):11, doi:10.1186/1471-227X-14-11.The original publication is available at http://www.biomedcentral.com/1471-227X/14/11Publication of this article was funded by the Stellenbosch University Open Access Fund.Abstract Background: Emergency healthcare workers, including trainees and individuals in related occupations are at heightened risk of developing posttraumatic stress disorder (PTSD) and depression owing to work-related stressors. We aimed to investigate the type, frequency, and severity of direct trauma exposure, posttraumatic stress symptoms and other psychopathology amongst paramedic trainees. In order to create a risk profile for individuals who are at higher occupational risk of developing PTSD, we examined risk and resilience factors that possibly contributed to the presence and severity of posttraumatic symptomatology. Methods: Paramedic trainees (n = 131) were recruited from a local university. A logistic regression analysis was conducted using the explanatory variables age, gender, population group, trauma exposure, depression, alcohol abuse, alcohol dependence, resilience and social support. Results: 94% of paramedic trainees had directly experienced trauma, with 16% meeting PTSD criteria. A high rate of depression (28%), alcohol abuse (23%) and chronic perceived stress (7%) and low levels of social support was found. The number of previous trauma exposures, depression, resilience and social support significantly predicted PTSD status and depression had a mediating effect. Conclusion: There is a need for efficient, ongoing screening of depressive and PTSD symptomatology in trauma exposed high risk groups so that early psychological supportive interventions can be offered. Background Emergency healthcare workers, including trainees and individuals in related occupations are at heightened risk of developing posttraumatic stress disorder (PTSD) and depression owing to work-related stressors. We aimed to investigate the type, frequency, and severity of direct trauma exposure, posttraumatic stress symptoms and other psychopathology amongst paramedic trainees. In order to create a risk profile for individuals who are at higher occupational risk of developing PTSD, we examined risk and resilience factors that possibly contributed to the presence and severity of posttraumatic symptomatology. Methods Paramedic trainees (n&#8201;=&#8201;131) were recruited from a local university. A logistic regression analysis was conducted using the explanatory variables age, gender, population group, trauma exposure, depression, alcohol abuse, alcohol dependence, resilience and social support. Results 94% of paramedic trainees had directly experienced trauma, with 16% meeting PTSD criteria. A high rate of depression (28%), alcohol abuse (23%) and chronic perceived stress (7%) and low levels of social support was found. The number of previous trauma exposures, depression, resilience and social support significantly predicted PTSD status and depression had a mediating effect. Conclusion There is a need for efficient, ongoing screening of depressive and PTSD symptomatology in trauma exposed high risk groups so that early psychological supportive interventions can be offered.Publishers' Versio

    Progress and Perspectives Beyond Traditional RAFT Polymerization

    Get PDF
    The development of advanced materials based on well‐defined polymeric architectures is proving to be a highly prosperous research direction across both industry and academia. Controlled radical polymerization techniques are receiving unprecedented attention, with reversible‐deactivation chain growth procedures now routinely leveraged to prepare exquisitely precise polymer products. Reversible addition‐fragmentation chain transfer (RAFT) polymerization is a powerful protocol within this domain, where the unique chemistry of thiocarbonylthio (TCT) compounds can be harnessed to control radical chain growth of vinyl polymers. With the intense recent focus on RAFT, new strategies for initiation and external control have emerged that are paving the way for preparing well‐defined polymers for demanding applications. In this work, the cutting‐edge innovations in RAFT that are opening up this technique to a broader suite of materials researchers are explored. Emerging strategies for activating TCTs are surveyed, which are providing access into traditionally challenging environments for reversible‐deactivation radical polymerization. The latest advances and future perspectives in applying RAFT‐derived polymers are also shared, with the goal to convey the rich potential of RAFT for an ever‐expanding range of high‐performance applications

    Physical Aging Investigations of a Spirobisindane-Locked Polymer of Intrinsic Microporosity

    Full text link
    Polymers of intrinsic microporosity (PIMs) have exceptional gas separation performance for a broad range of applications. However, PIMs are highly susceptible to physical aging, which drastically reduces their long-term performance over time. In this work, we leverage complementary experimental and density functional theory (DFT) studies to decipher the inter-/intrachain changes that occur during aging of the prototypical PIM-1 and its rigidified analogue PIM-C1. By elucidating this hereto unexplored aging behavior, we reveal that the dramatic decrease in gas permeability of PIM materials during aging stems from a loss of fractional free volume (FFV) due to PIM chain relaxations induced by π-πinteractions, hydrogen bonding, or van der Waals' forces. While the PIM-1 based membranes displayed enhanced gas pair selectivities after aging, the PIM-C1 based membranes showed an opposite trend with unexpected reductions for CO2/N2 and CO2/CH4. This is due to the reductions in CO2/N2 and CO2/CH4 solubility (S) selectivities and, unlike PIM-1, the spirobisindane locked PIM-C1 (i.e., maintenance of micropore sizes) has a stable diffusivity (D) selectivities that cannot offset such reductions. These fundamental insights into the intrinsic relaxation of different PIM polymer chains during physical aging can guide the future design of high-performance PIM materials with enhanced anti-aging properties
    corecore