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Tu PHT, Anlay DZ, Dippenaar A, Conceição EC, Loos J, Van Rie A. Bedaquiline resistance probability to guide treatment decision making for rifampicin-resistant tuberculosis: insights from a qualitative study. BMC Infect Dis 2022; 22:876. [PMID: 36418994 PMCID: PMC9682818 DOI: 10.1186/s12879-022-07865-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 11/10/2022] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Bedaquiline (BDQ) is a core drug for rifampicin-resistant tuberculosis (RR-TB) treatment. Accurate prediction of a BDQ-resistant phenotype from genomic data is not yet possible. A Bayesian method to predict BDQ resistance probability from next-generation sequencing data has been proposed as an alternative. METHODS We performed a qualitative study to investigate the decision-making of physicians when facing different levels of BDQ resistance probability. Fourteen semi-structured interviews were conducted with physicians experienced in treating RR-TB, sampled purposefully from eight countries with varying income levels and burden of RR-TB. Five simulated patient scenarios were used as a trigger for discussion. Factors influencing the decision of physicians to prescribe BDQ at macro-, meso- and micro levels were explored using thematic analysis. RESULTS The perception and interpretation of BDQ resistance probability values varied widely between physicians. The limited availability of other RR-TB drugs and the high cost of BDQ hindered physicians from altering the BDQ-containing regimen and incorporating BDQ resistance probability in their decision-making. The little experience with BDQ susceptibility testing and whole-genome sequencing results, and the discordance between phenotypic susceptibility and resistance probability were other barriers for physicians to interpret the resistance probability estimates. Especially for BDQ resistance probabilities between 25% and 70%, physicians interpreted the resistance probability value dynamically, and other factors such as clinical and bacteriological treatment response, history of exposure to BDQ, and resistance profile were often considered more important than the BDQ probability value for the decision to continue or stop BDQ. In this grey zone, some physicians opted to continue BDQ but added other drugs to strengthen the regimen. CONCLUSIONS This study highlights the complexity of physicians' decision-making regarding the use of BDQ in RR-TB regimens for different levels of BDQ resistance probability.. Ensuring sufficient access to BDQ and companion drugs, improving knowledge of the genotype-phenotype association for BDQ resistance, availability of a rapid molecular test, building next-generation sequencing capacity, and developing a clinical decision support system incorporating BDQ resistance probability will all be essential to facilitate the implementation of BDQ resistance probability in personalizing treatment for patients with RR-TB.
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Affiliation(s)
- Pham Hien Trang Tu
- grid.5284.b0000 0001 0790 3681Department of Family Medicine and Population Health, Faculty of Medicine and Health Sciences, University of Antwerp, Doornstraat 331, 2610 Antwerp, Belgium
| | - Degefaye Zelalem Anlay
- grid.5284.b0000 0001 0790 3681Department of Family Medicine and Population Health, Faculty of Medicine and Health Sciences, University of Antwerp, Doornstraat 331, 2610 Antwerp, Belgium ,grid.59547.3a0000 0000 8539 4635Department of Community Health Nursing, School of Nursing, College of Medicine and Health Science, University of Gondar, Gondar, Ethiopia
| | - Anzaan Dippenaar
- grid.5284.b0000 0001 0790 3681Department of Family Medicine and Population Health, Faculty of Medicine and Health Sciences, University of Antwerp, Doornstraat 331, 2610 Antwerp, Belgium
| | - Emilyn Costa Conceição
- grid.11956.3a0000 0001 2214 904XDepartment of Science and Innovation, National Research Foundation Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Jasna Loos
- grid.5284.b0000 0001 0790 3681Dean’s Office, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Annelies Van Rie
- grid.5284.b0000 0001 0790 3681Department of Family Medicine and Population Health, Faculty of Medicine and Health Sciences, University of Antwerp, Doornstraat 331, 2610 Antwerp, Belgium
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EzEldeen M, Loos J, Mousavi Nejad Z, Cristaldi M, Murgia D, Braem A, Jacobs R. 3D-printing-assisted fabrication of chitosan scaffolds from different sources and cross-linkers for dental tissue engineering. Eur Cell Mater 2021; 41:485-501. [PMID: 33948929 DOI: 10.22203/ecm.v041a31] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The aim of the present study was to fabricate and characterise chitosan scaffolds from animal and fungal sources, with or without gelatine as a co-polymer, and cross-linked to 3-glycidyloxyproply trimethoxysilane (GPTMS) or genipin for application in dental root tissue engineering. Chitosan-based scaffolds were prepared by the emulsion freeze-drying technique. Scanning electron microscopy (SEM) and nano-focus computed tomography (nano-CT) were used to characterise scaffold microstructure. Chemical composition and cross-linking were evaluated by Fourier transform infrared-attenuated total reflectance spectroscopy. Compression tests were performed to evaluate scaffold mechanical properties. Scaffold degradation was evaluated by gravimetric method and SEM. Scaffold bioactivity immersed in simulated body fluid was evaluated by SEM, with associated electron dispersive X-ray spectroscopy, and apatite formation was examined by X-ray diffraction. Finally, human dental pulp stem cells (hDPSCs) viability was evaluated. The fabrication method used was successful in producing scaffolds with organised porosity. Chitosan source (animal vs. fungal), co-polymerisation with gelatine and cross-linking using GPTMS or genipin had a significant effect on scaffold properties and hDPSCs response. Chitosan-genipin (CS-GEN) scaffolds had the largest pore diameter, while the chitosan-gelatine-GPTMS (CS-GEL-GPTMS) scaffolds had the smallest. Animal chitosan-gelatine co-polymerisation increased scaffold compressive strength, while fungal chitosan scaffolds (fCS-GEL-GPTMS) had the fastest degradation rate, losing 80 % of their weight by day 21. Gelatine co-polymerisation and GPTMS cross-linking enhanced chitosan scaffolds bioactivity through the formation of an apatite layer as well as improved hDPSCs attachment and viability. Tailored chitosan scaffolds with tuned properties and favourable hDPSCs response can be obtained for regenerative dentistry applications.
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Apers H, Nöstlinger C, Van Beckhoven D, Deblonde J, Apers L, Verheyen K, Loos J. Identifying key elements to inform HIV-testing interventions for primary care in Belgium. Health Promot Int 2020; 35:301-311. [PMID: 31056680 PMCID: PMC7250498 DOI: 10.1093/heapro/daz037] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
General practitioners (GPs) play a key role in reducing the hidden HIV-epidemic, but many diagnostic opportunities are missed in primary care. This study aimed at informing the development of an HIV-testing intervention for GPs in Flanders (Belgium) using formative research with a participatory approach. Through the active involvement of an advisory board and 16 group discussions with 122 Flemish GPs, GPs’ current HIV-testing practices and perceived practical relevance of 2 distinct HIV-testing strategies (i.e. provider-initiated testing of key populations and indicator condition-based testing) were explored in terms of their relevance and feasibility in routine primary care. Self-reported HIV-testing practices revealed that most tests performed were patient-initiated, pretest counseling was rarely done, and post-test counseling was offered mainly for patients with an HIV-diagnosis. GPs reported multiple barriers to provider-initiated HIV-testing, i.e. personal discomfort, fear of offending their patient, limited knowledge of benefits of early HIV-diagnosis, misconceptions about HIV-risks, lack of guidelines and time. Difficulties to identify patient’s sexual orientation or ethical concerns were mentioned as barriers for target group-based HIV testing. GPs assessed the current list of 64 indicator conditions as too difficult to integrate in routine care, deeming a reduced list of GP-relevant conditions as more feasible. Combined strategies (i.e. target group- and indicator-based testing) supported by official screening recommendations were perceived as successful strategies for provider-initiated HIV-testing in primary care. This formative research delivered qualitative evidence for the development of an HIV-testing intervention for primary care settings.
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Affiliation(s)
- Hanne Apers
- Group HIV and Sexual Health, Department of Public Health, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerp, Belgium
- Corresponding author. E-mail:
| | - Christiana Nöstlinger
- Group HIV and Sexual Health, Department of Public Health, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerp, Belgium
- Faculty of Psychology, University of Vienna, Vienna, Austria
| | - Dominique Van Beckhoven
- Epidemiology of Infectious Diseases Unit, Department of Public Health and Surveillance, Sciensano - Belgian Scientific Institute of Public Health, Ixelles, Belgium
| | - Jessika Deblonde
- Epidemiology of Infectious Diseases Unit, Department of Public Health and Surveillance, Sciensano - Belgian Scientific Institute of Public Health, Ixelles, Belgium
| | - Ludwig Apers
- HIV/STI clinic, Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Katleen Verheyen
- General Practitioner, Opglabbeek, Belgium
- ELIZA - Center for General Practice, Department of Primary & Interdisciplinary Care Antwerp, University of Antwerp, Antwerp, Belgium
| | - Jasna Loos
- Group HIV and Sexual Health, Department of Public Health, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerp, Belgium
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Dias S, Loos J, Gama A, Simões D, Nöstlinger C. Risk for HIV acquisition among sub-Saharan African migrant travelers in Belgium and Portugal. Eur J Public Health 2020. [DOI: 10.1093/eurpub/ckaa165.563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Migrants often travel back to the origin countries and to other European states after settling in the residence country. Mobility along with structural vulnerabilities may increase HIV acquisition risk. Knowledge on HIV risk exposure when traveling is limited, yet crucial to inform prevention. This study aims to explore risky sexual behaviors and assess HIV prevalence among sub-Saharan African migrants (SAMs) who travel, residing in two European cities.
Two cross-sectional biobehavioral surveys were conducted in Lisbon and Antwerp with a venue-based sample of 1508 SAMs. Descriptive and multivariable logistic regression analyses were performed to examine travel patterns and associated sexual risk behaviors.
Overall, 68.4% of participants had traveled to other countries after settling in the residence country; 41% had traveled back to Africa and within Europe, 25.2% only to Africa and 33.8% only to Europe. Among travelers who reported sexual encounters abroad (49.2%), condomless sex at last intercourse was high both abroad (62.5%) and in the host country (70.7%). Odds of condomless sex at the last sexual encounter in the host country were five times higher among those who also reported no condom use abroad [OR: 5.32; 95% CI: 2.98-9.25], controlling for gender, age, educational level, relationship status, survey country, partner type and origin, and number of sexual partners over the last year. Condomless sex was higher with a regular partner and with an African partner, both abroad (79.9% and 67.5%, respectively) and in the host country (81.3% and 74.6%, respectively). Among the 75 participants who tested HIV-positive (around 5%), more than half had travelled to other countries; of these, about half reported condomless sex with their last sexual partner abroad.
SAMs are a mobile population and are exposed to sexual HIV risk both while traveling and in host countries. Prevention interventions should address the complex interplay between migrants' mobility and HIV risk.
Key messages
Migrants often travel to their origin home countries and other destinations after having settled in host countries, and this mobility increases exposure to HIV risk. A transnational perspective on HIV prevention and sexual health promotion is needed for effectively reducing migrants’ HIV risk related to their mobility.
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Affiliation(s)
- S Dias
- NOVA National School of Public Health, Public Health Research Centre & Global Health and Tropical Medicine, Universidade NOVA de Lisboa, Lisbon, Portugal
- Comprehensive Health Research Centre, Lisbon, Portugal
| | - J Loos
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - A Gama
- NOVA National School of Public Health, Public Health Research Centre & Global Health and Tropical Medicine, Universidade NOVA de Lisboa, Lisbon, Portugal
- Comprehensive Health Research Centre, Lisbon, Portugal
| | - D Simões
- Grupo de Ativistas em Tratamentos, Lisbon, Portugal
| | - C Nöstlinger
- Grupo de Ativistas em Tratamentos, Lisbon, Portugal
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Apers H, Vuylsteke B, Loos J, Smekens T, Deblonde J, Van Beckhoven D, Nöstlinger C. Development and Evaluation of an HIV-Testing Intervention for Primary Care: Protocol for a Mixed Methods Study. JMIR Res Protoc 2020; 9:e16486. [PMID: 32497016 PMCID: PMC7459432 DOI: 10.2196/16486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 12/09/2019] [Accepted: 12/10/2019] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Late diagnosis of HIV fosters HIV transmission and may lead to hidden HIV epidemics. In Belgium, mathematical modeling indicates a high prevalence of undiagnosed HIV infections among men who have sex with men of non-Belgian origin and among sub-Saharan African migrants. Promotion of HIV testing facilitates early diagnosis, but diagnostic opportunities are missed in primary care. OBJECTIVE The intervention study aims to enhance provider-initiated HIV testing by GPs. This protocol presents the conceptual development, implementation, and evaluation of an HIV-testing intervention for Flemish general practitioners (GPs). METHODS A mixed methods evaluation design is used. Guided by a simplified intervention mapping approach, an evidence-based intervention was developed in collaboration, guided by an interdisciplinary advisory board. The intervention consisted of an evidence-based tool (ie, "HIV-testing advice for primary care") to support GPs in provider-initiated HIV testing. A modified stepped-wedge design compare two different intervention levels: (1) online dissemination of the HIV-testing advice and (2) dissemination with additional group-level training. Both conditions were compared against a control condition with no intervention. The effect of the intervention was measured using Poisson regression for national surveillance data. The primary outcome was the number of HIV diagnoses made by GPs. Secondary outcomes were HIV diagnoses among groups at risk for undiagnosed HIV, distribution of new diagnoses by CD4 cell count, number of HIV tests prescribed by GPs, and rate of new diagnoses by tests. To evaluate the intervention's implementation, the GPs' fidelity to the intervention and the intervention's feasibility and acceptability by GPs were assessed through (web-based) surveys and in-depth telephone interviews. RESULTS The study was funded in 2016 and ethically approved in January 2017. The implementation of the intervention started in January 2017 and ended in December 2018. Data was completed in October 2019 and was the starting point for the ongoing data analysis. The results are expected to be published in the second half of 2020. CONCLUSIONS Results of the intervention study will provide useful information on the intervention's effectiveness among Flemish GPs and can inform further development of official testing guidelines. Limitations of this real-life intervention approach are potential spill-over effects, delay in access to surveillance data, and little detailed information on HIV-testing practices among GPs. TRIAL REGISTRATION ClinicalTrials.gov NCT04056156; https://clinicaltrials.gov/ct2/show/NCT04056156. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID) DERR1-10.2196/16486.
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Affiliation(s)
- Hanne Apers
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium.,Centre for Migration and Intercultural Studies, University of Antwerp, Antwerp, Belgium
| | - Bea Vuylsteke
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Jasna Loos
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium.,Domus Medica, Antwerp, Belgium.,Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Tom Smekens
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Jessika Deblonde
- Epidemiology of Infectious Diseases Unit, Department of Public Health and Surveillance, Belgian Scientific Institute of Public Health (Sciensano), Brussels, Belgium
| | - Dominique Van Beckhoven
- Epidemiology of Infectious Diseases Unit, Department of Public Health and Surveillance, Belgian Scientific Institute of Public Health (Sciensano), Brussels, Belgium
| | - Christiana Nöstlinger
- Epidemiology of Infectious Diseases Unit, Department of Public Health and Surveillance, Belgian Scientific Institute of Public Health (Sciensano), Brussels, Belgium
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Dias S, Gama A, Loos J, Roxo L, Simões D, Nöstlinger C. The role of mobility in sexual risk behaviour and HIV acquisition among sub-Saharan African migrants residing in two European cities. PLoS One 2020; 15:e0228584. [PMID: 32023309 PMCID: PMC7001961 DOI: 10.1371/journal.pone.0228584] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 01/18/2020] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Migrants from high endemic countries accounted for 18% of newly diagnosed HIV infections in Europe in 2017. Knowledge on the link between HIV risk and post-migration travels and their impact on HIV acquisition is scarce, but critical to inform prevention. This study aims to explore risky sexual behaviour and HIV-acquisition among sub-Saharan African migrants, and to assess post-migration mobility as a determinant of sexual risk behaviour. METHODS Data from two cross-sectional bio-behavioural surveys to assess HIV-prevalence conducted in Lisbon and Antwerp were analysed to explore migration-related characteristics, travel patterns, and sexual risk taking in the host country and abroad. Bi- and multivariate associations were estimated through adjusted odds ratios and 95% confidence intervals; multivariable logistic regression determined factors associated with condomless sexual intercourse. RESULTS Among N = 1508 participants above 18 years (58% males), 68% travelled post-migration (49.2% reported intercourse abroad). The overall proportion of condomless sex at last sexual intercourse was high (68.1%). The odds of condomless sex in the host country was five times higher when the last sexual intercourse abroad was also condomless [OR:5.32; 95%CI:2.98-9.25]. About half of the travellers reported concurrency, i.e. a regular partner in the host country while having other sexual partners abroad. Almost three percent of the participants reported being HIV+, but 5% had a reactive HIV test-result, with similar proportions among travellers and non-travellers. Also, among the n = 75 participants with reactive HIV test-results, condomless sex occurred (n = 40) and was associated with mobility. CONCLUSIONS Sub-Saharan African migrants are mobile and engage in sexual risk behaviours in the countries of residence and while travelling, increasing risk of post-migration HIV-acquisition. A transnational perspective on HIV prevention and sexual health promotion is needed for effectively reducing migrants' HIV risk related to their mobility.
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Affiliation(s)
- Sónia Dias
- NOVA National School of Public Health, Public Health Research Centre & Global Health and Tropical Medicine, Universidade NOVA de Lisboa, Lisboa, Portugal
- Comprehensive Health Research Centre (CHRC), Lisboa, Portugal
- * E-mail:
| | - Ana Gama
- NOVA National School of Public Health, Public Health Research Centre & Global Health and Tropical Medicine, Universidade NOVA de Lisboa, Lisboa, Portugal
- Comprehensive Health Research Centre (CHRC), Lisboa, Portugal
| | - Jasna Loos
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Luis Roxo
- NOVA National School of Public Health, Public Health Research Centre & Global Health and Tropical Medicine, Universidade NOVA de Lisboa, Lisboa, Portugal
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Deblonde J, Van Beckhoven D, Loos J, Boffin N, Sasse A, Nöstlinger C, Supervie V. HIV testing within general practices in Europe: a mixed-methods systematic review. BMC Public Health 2018; 18:1191. [PMID: 30348140 PMCID: PMC6196459 DOI: 10.1186/s12889-018-6107-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 10/10/2018] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Late diagnosis of HIV infection remains a key challenge in Europe. It is acknowledged that general practitioners (GPs) may contribute greatly to early case finding, yet there is evidence that many diagnostic opportunities are being missed. To further promote HIV testing in primary care and to increase the utility of available research, the existing evidence has been synthesised in a systematic review adhering to the PRISMA guidelines. METHODS The databases PubMed, Scopus and Embase were searched for the period 2006-2017. Two authors judged independently on the eligibility of studies. Through a mixed-methods systematic review of 29 studies, we provide a description of HIV testing in general practices in Europe, including barriers and facilitators. RESULTS The findings of the study show that although various approaches to target patients are used by GPs, most tests are still carried out based on the patient's request. Several barriers obstruct HIV testing in general practice. Included are a lack of communication skills on sexual health, lack of knowledge about HIV testing recommendations and epidemic specificities, difficulties with using the complete list of clinical HIV indicator diseases and lack of experience in delivering and communicating test results. The findings also suggest that the provision of specific training, practical tools and promotion programmes has an impact on the testing performance of GPs. CONCLUSIONS GPs could have an increased role in provider-initiated HIV-testing for early case finding. To achieve this objective, solutions to the reported barriers should be identified and testing criteria adapted to primary healthcare defined. Providing guidance and training to better identify priority groups for HIV testing, as well as information on the HIV epidemic's characteristics, will be fundamental to increasing awareness and testing by GPs.
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Affiliation(s)
- Jessika Deblonde
- Sciensano, Health Services Research, Juliette Wytsmanstraat 14, 1050 Brussels, Belgium
| | | | - Jasna Loos
- Department of Public Health, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerp, Belgium
| | - Nicole Boffin
- Sciensano, Health Services Research, Juliette Wytsmanstraat 14, 1050 Brussels, Belgium
| | - André Sasse
- Sciensano, Health Services Research, Juliette Wytsmanstraat 14, 1050 Brussels, Belgium
| | - Christiana Nöstlinger
- Department of Public Health, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerp, Belgium
- Faculty of Psychology, University of Vienna, Vienna, Austria
| | - Virginie Supervie
- Institut Pierre Louis d’Epidémiologie et de Santé Publique, INSERM, Sorbonne Université, 56 Bd. Vincent Auriol, CS 81393, 75646 Paris Cedex 13, France
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Loos J, Nöstlinger C, Reyniers T, Colebunders R, Jespers V, Manirankunda L, Berghe WV, Vuylsteke B, Laga M. PrEP for African migrants in Europe? A research agenda. Lancet HIV 2018; 3:e505-e507. [PMID: 27788864 DOI: 10.1016/s2352-3018(16)30173-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 10/05/2016] [Accepted: 10/05/2016] [Indexed: 11/16/2022]
Affiliation(s)
- Jasna Loos
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | | | - Thijs Reyniers
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Robert Colebunders
- Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Vicky Jespers
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Lazare Manirankunda
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Wim Vanden Berghe
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium; Sociaal Cultureel Plan Bureau, The Hague, Netherlands
| | - Bea Vuylsteke
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Marie Laga
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
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Dias S, Loos J, Roxo L, Gama A, Simões D, Noestlinger C. 5.5-O2Understanding the links between mobility, risky sexual behaviors and HIV among sub-Saharan African migrants (SAMs): a study in two European cities. Eur J Public Health 2018. [DOI: 10.1093/eurpub/cky047.186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- S Dias
- Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa, Portugal
| | - J Loos
- Institute of Tropical Medicine, Department of Public Health, Antwerp, Belgium
| | - L Roxo
- Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa, Portugal
| | - A Gama
- Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa, Portugal
| | - D Simões
- GAT - Grupo de Ativistas em Tratamentos, Portugal
| | - C Noestlinger
- Institute of Tropical Medicine, Department of Public Health, Antwerp, Belgium
- University of Vienna, Faculty of Psychology, Austria
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Affiliation(s)
| | - Jasna Loos
- Department of Public Health, Institute of Tropical Medicine, Antwerp 2000, Belgium
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Abstract
Adolescents living with HIV (ALHIV) face many psychosocial challenges, including HIV disclosure to others. Given the importance of socialization during the adolescent transition process, this study investigated the psychological and social factors influencing self-disclosure of own HIV status to peers. We examined social HIV self-disclosure to peers, and its relationship to perceived HIV-related stigma, self-efficacy to disclose, self-esteem, and social support among a sample of n = 582 ALHIV aged 13–17 years in Kampala, Uganda, and Western Kenya. Data were collected between February and April 2011. Among them, 39% were double orphans. We conducted a secondary data analysis to assess the degree of social disclosure, reactions received, and influencing factors. Interviewer-administered questionnaires assessed medical, socio-demographic, and psychological variables (Rosenberg self-esteem scale; self-efficacy to disclose to peers), HIV-related stigma (10-item stigma scale), and social support (family–life and friends). Descriptive, bivariate, and logistic regression analyses were performed with social self-disclosure to peers with gender as covariates. Almost half of ALHIV had told nobody (except health-care providers) about their HIV status, and about 18% had disclosed to either one of their friends, schoolmates, or a boy- or girlfriend. Logistic regression models revealed that having disclosed to peers was significantly related to being older, being a paternal orphan, contributing to family income, regular visits to the HIV clinic, and greater social support through peers. Low self-efficacy to disclose was negatively associated to the outcome variable. While social self-disclosure was linked to individual factors such as self-efficacy, factors relating to the social context and adolescents’ access to psychosocial resources play an important role. ALHIV need safe environments to practice disclosure skills. Interventions should enable them to make optimal use of available psychosocial resources even under constraining conditions such as disruptive family structures.
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Affiliation(s)
| | - Sabrina Bakeera-Kitaka
- c Baylor-Uganda , Kampala , Uganda.,d Department of Paediatrics , Makerere University , Kampala , Uganda
| | - Jozefien Buyze
- b Department of Clinical Sciences , Institute of Tropical Medicine , Antwerp , Belgium
| | - Jasna Loos
- a Department of Public Health , Institute of Tropical Medicine , Antwerp , Belgium
| | - Anne Buvé
- a Department of Public Health , Institute of Tropical Medicine , Antwerp , Belgium
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Loos J, Nöstlinger C, Vuylsteke B, Deblonde J, Ndungu M, Kint I, Manirankunda L, Reyniers T, Adobea D, Laga M, Colebunders R. First HIV prevalence estimates of a representative sample of adult sub-Saharan African migrants in a European city. Results of a community-based, cross-sectional study in Antwerp, Belgium. PLoS One 2017; 12:e0174677. [PMID: 28380051 PMCID: PMC5381894 DOI: 10.1371/journal.pone.0174677] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 03/12/2017] [Indexed: 11/18/2022] Open
Abstract
Introduction While sub-Saharan African migrants are the second largest group affected by HIV in Europe, sound HIV prevalence estimates based on representative samples of these heterogeneous communities are lacking. Such data are needed to inform prevention and public health policy. Methods This community-based, cross-sectional study combined oral fluid HIV testing with an electronic behavioral survey. Adopting a two-stage time location sampling HIV prevalence estimates for a representative sample of adult sub-Saharan African migrants in Antwerp, Belgium were obtained. Sample proportions and estimated adjusted population proportions were calculated for all variables. Univariable and multivariable logistic regression analysis explored factors independently associated with HIV infection. Results Between December 2013 and October 2014, 744 sub-Saharan African migrants were included (37% women). A substantial proportion was socially, legally and economically vulnerable: 21% were probably of undocumented status, 63% had financial problems in the last year and 9% lacked stable housing. Sexual networks were mostly African and crossed national borders, i.e. sexual encounters during travels within Europa and Africa. Concurrency is common, 34% of those in a stable relationship had a partner on the side in the last year. HIV prevalence was 5.9%(95%CI:3.4%-10.1%) among women and 4.2% (95%CI:1.6%-10.6%) among men. Although high lifetime HIV testing was reported at community level (73%), 65.2% (CI95%:32.4%-88.0%) of sub-Saharan African migrants were possibly undiagnosed. Being 45 years or older, unprotected sex when travelling within Europe in the last year, high intentions to use condoms, being unaware of their last sexual partners’ HIV status, recent HIV testing and not having encountered partner violence in the last year were independently associated with HIV infection in multivariable logical regression. In univariable analysis, HIV infection was additionally associated to unemployment. Conclusions This is the first HIV prevalence study among adult sub-Saharan African migrants resettling in a European city based on a representative sample. HIV prevalence was high and could potentially increase further due to the high number of people with an undiagnosed HIV infection, social vulnerability, high levels of concurrency and mainly African sexual networks. Given this population’s mobility, an aligned European combination prevention approach addressing these determinants is urgently needed.
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Affiliation(s)
- Jasna Loos
- HIV and Sexual Health Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
- * E-mail:
| | - Christiana Nöstlinger
- HIV and Sexual Health Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Bea Vuylsteke
- HIV and Sexual Health Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Jessika Deblonde
- Epidemiology of Infectious Diseases Unit, Department of Public Health and Surveillance, Scientific Institute of Public Health, Brussels, Belgium
| | - Morgan Ndungu
- Community researcher of the TOGETHER Project, HIV and Sexual Health Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Ilse Kint
- AIDS Reference Center, Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Lazare Manirankunda
- HIV and Sexual Health Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Thijs Reyniers
- HIV and Sexual Health Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Dorothy Adobea
- Community researcher of the TOGETHER Project, HIV and Sexual Health Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Marie Laga
- HIV and Sexual Health Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Robert Colebunders
- AIDS Reference Center, Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
- Epidemiology for Global Health Institute, Faculty of Medicine & Health Sciences, University of Antwerp, Antwerp, Belgium
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Loos J, Manirankunda L, Platteau T, Albers L, Fransen K, Vermoesen T, Namanya F, Nöstlinger C. Acceptability of a Community-Based Outreach HIV-Testing Intervention Using Oral Fluid Collection Devices and Web-Based HIV Test Result Collection Among Sub-Saharan African Migrants: A Mixed-Method Study. JMIR Public Health Surveill 2016; 2:e33. [PMID: 27493067 PMCID: PMC4990717 DOI: 10.2196/publichealth.5519] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 05/11/2016] [Accepted: 06/17/2016] [Indexed: 12/03/2022] Open
Abstract
Background Late human immunodeficiency virus (HIV) diagnosis is common among sub-Saharan African migrants. To address their barriers to HIV testing uptake and improve timely HIV diagnoses and linkage to care, the outreach HIV testing intervention, “swab2know,” was developed. It combined a community-based approach with innovative testing methods: oral fluid self-sampling and the choice between Web-based HIV test result collections using a secured website or post-test counseling at a sexual health clinic. The sessions included an informational speech delivered by a physician of sub-Saharan African origin and testimonies by community members living with HIV. Objectives The objectives of this study were to evaluate the intervention’s acceptability among sub-Saharan African migrants and its potential to reach subgroups at higher risk for HIV infection and to identify facilitators and barriers for HIV testing uptake. Methods This mixed-method study combined qualitative (participant observations and informal interviews with testers and nontesters) and quantitative data (paper–pencil survey, laboratory data, and result collection files). Data were analyzed using a content analytical approach for qualitative and univariate analysis for quantitative data. Results A total of 10 testing sessions were organized in sub-Saharan African migrant community venues in the city of Antwerp, Belgium, between December 2012 and June 2013. Overall, 18.2% of all people present (N=780) underwent HIV testing; 29.8% of them tested for HIV for the first time, 22.3% did not have a general practitioner, and 21.5% reported 2 or more sexual partners (last 3 months). Overall, 56.3% of participants chose to collect their HIV test results via the protected website. In total, 78.9% collected their results. The qualitative analysis of 137 participant observation field notes showed that personal needs and Internet literacy determined the choice of result collection method. Generally, the oral fluid collection devices were well accepted mainly because sub-Saharan African migrants dislike blood taking. For some participants, the method raised concerns about HIV transmission via saliva. The combination of information sessions, testimonies, and oral fluid collection devices was perceived as effectively reducing thresholds to participation. Acceptability of the intervention differed between individual participants and settings. Acceptance was higher among women, in churches and settings where community leaders were engaged in HIV awareness raising. Higher preventive outcomes were observed in settings with lower acceptance. The presence of the intervention team visualized the magnitude of the HIV epidemic to the public and promoted HIV testing uptake at large, for example, those who declined indicated they would take up testing later. Conclusions When accompanied by tailored provision of information, outreach HIV testing interventions adopting a community-based approach and innovative methods such as Web-based result collection and oral fluid collection devices are acceptable and reduce thresholds for HIV testing uptake. The swab2know intervention was able to reach sub-Saharan African migrants at risk of HIV infection, and with limited access to regular HIV testing. Among nontesters, the intervention contributed to awareness raising and therefore has a place in a multipronged HIV test promotion strategy.
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Affiliation(s)
- Jasna Loos
- HIV and Sexual Health Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium.
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Loos J, Vuylsteke B, Manirankunda L, Deblonde J, Kint I, Namanya F, Fransen K, Colebunders R, Laga M, Adobea D, Nöstlinger C. TOGETHER Project to Increase Understanding of the HIV Epidemic Among Sub-Saharan African Migrants: Protocol of Community-Based Participatory Mixed-Method Studies. JMIR Res Protoc 2016; 5:e48. [PMID: 26988266 PMCID: PMC4816927 DOI: 10.2196/resprot.5162] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 11/18/2015] [Accepted: 11/29/2015] [Indexed: 11/20/2022] Open
Abstract
Background Sub-Saharan African Migrants (SAM) are the second largest group affected by HIV/AIDS in Belgium and the rest of Western Europe. Increasing evidence shows that, more than previously thought, SAM are acquiring HIV in their host countries. This calls for a renewed focus on primary prevention. Yet, knowledge on the magnitude of the HIV epidemic among SAM (HIV prevalence estimates and proportions of undiagnosed HIV infections) and underlying drivers are scarce and limit the development of such interventions. Objective By applying a community-based participatory and mixed-methods approach, the TOGETHER project aims to deepen our understanding of HIV transmission dynamics, as well as inform future primary prevention interventions for this target group. Methods The TOGETHER project consists of a cross-sectional study to assess HIV prevalence and risk factors among SAM visiting community settings in Antwerp city, Belgium, and links an anonymous electronic self-reported questionnaire to oral fluid samples. Three formative studies informed this method: (1) a social mapping of community settings using an adaptation of the PLACE method; (2) a multiple case study aiming to identify factors that increase risk and vulnerability for HIV infection by triangulating data from life history interviews, lifelines, and patient files; and (3) an acceptability and feasibility study of oral fluid sampling in community settings using participant observations. Results Results have been obtained from 4 interlinked studies and will be described in future research. Conclusions Combining empirically tested and innovative epidemiological and social science methods, this project provides the first HIV prevalence estimates for a representative sample of SAM residing in a West European city. By triangulating qualitative and quantitative insights, the project will generate an in-depth understanding of the factors that increase risk and vulnerability for HIV infection among SAM. Based on this knowledge, the project will identify priority subgroups within SAM communities and places for HIV prevention. Adopting a community-based participatory approach throughout the full research process should increase community ownership, investment, and mobilization for HIV prevention.
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Affiliation(s)
- Jasna Loos
- HIV and Sexual Health Unit, Department of Public Health, Institute of Tropical Medicine, Antwerpen, Belgium.
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Nöstlinger C, Loos J. Involving lay community researchers in epidemiological research: experiences from a seroprevalence study among sub-Saharan African migrants. AIDS Care 2016; 28 Suppl 1:119-23. [PMID: 26885938 PMCID: PMC4828617 DOI: 10.1080/09540121.2016.1146398] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 01/20/2016] [Indexed: 11/09/2022]
Abstract
Community-based participatory research (CBPR) has received considerable attention during past decades as a method to increase community ownership in research and prevention. We discuss its application to epidemiological research using the case of second-generation surveillance conducted among sub-Saharan African (SSA) migrants in Antwerp city. To inform evidence-based prevention planning for this target group, this HIV-prevalence study used two-stage time-location sampling preceded by formative research. Extensive collaborative partnerships were built with community organizations, a Community Advisory Board provided input throughout the project, and community researchers were trained to participate in all phases of the seroprevalence study. Valid oral fluid samples for HIV testing were collected among 717 SSA migrants and linked to behavioural data assessed through an anonymous survey between December 2013 and August 2014. A qualitative content analysis of various data sources (extensive field notes, minutes of intervision, and training protocols) collected at 77 data collection visits in 51 settings was carried out to describe experiences with challenges and opportunities inherent to the CBPR approach at three crucial stages of the research process: building collaborative partnerships; implementing the study; dissemination of findings including prevention planning. The results show that CBPR is feasible in conducting scientifically sound epidemiological research, but certain requirements need to be in place. These include among others sufficient resources to train, coordinate, and supervise community researchers; continuity in the implementation; transparency about decision-taking and administrative procedures, and willingness to share power and control over the full research process. CBPR contributed to empowering community researchers on a personal level, and to create greater HIV prevention demand in the SSA communities.
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Affiliation(s)
| | - Jasna Loos
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
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Platteau T, Fransen K, Apers L, Kenyon C, Albers L, Vermoesen T, Loos J, Florence E. Swab2know: An HIV-Testing Strategy Using Oral Fluid Samples and Online Communication of Test Results for Men Who Have Sex With Men in Belgium. J Med Internet Res 2015; 17:e213. [PMID: 26330138 PMCID: PMC4642797 DOI: 10.2196/jmir.4384] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 08/04/2015] [Accepted: 08/05/2015] [Indexed: 11/26/2022] Open
Abstract
Background As HIV remains a public health concern, increased testing among those at risk for HIV acquisition is important. Men who have sex with men (MSM) are the most important group for targeted HIV testing in Europe. Several new strategies have been developed and implemented to increase HIV-testing uptake in this group, among them the Swab2know project. Objective In this project, we aim to assess the acceptability and feasibility of outreach and online HIV testing using oral fluid samples as well as Web-based delivery of test results. Methods Sample collection happened between December 2012 and April 2014 via outreach and online sampling among MSM. Test results were communicated through a secured website. HIV tests were executed in the laboratory. Each reactive sample needed to be confirmed using state-of-the-art confirmation procedures on a blood sample. Close follow-up of participants who did not pick up their results, and those with reactive results, was included in the protocol. Participants were asked to provide feedback on the methodology using a short survey. Results During 17 months, 1071 tests were conducted on samples collected from 898 men. Over half of the samples (553/1071, 51.63%) were collected during 23 outreach sessions. During an 8-month period, 430 samples out of 1071 (40.15%) were collected from online sampling. Additionally, 88 samples out of 1071 (8.22%) were collected by two partner organizations during face-to-face consultations with MSM and male sex workers. Results of 983 out of 1071 tests (91.78%) had been collected from the website. The pickup rate was higher among participants who ordered their kit online (421/430, 97.9%) compared to those participating during outreach activities (559/641, 87.2%; P<.001). MSM participating during outreach activities versus online participants were more likely to have never been tested before (17.3% vs 10.0%; P=.001) and reported more sexual partners in the 6 months prior to participation in the project (mean 7.18 vs 3.23; P<.001). A total of 20 participants out of 898 (2.2%) were confirmed HIV positive and were linked to care. Out of 1071 tests, 28 (2.61%) with a weak reactive result could not be confirmed, and were thereby classified as false reactive results.
Most of the 388 participants who completed posttest surveys (388/983, 39.5%) were very positive about their experience. The vast majority (371/388, 95.6%) were very satisfied, while 17 out of 388 (4.4%) reported mixed feelings. Conclusions Despite a high yield and a considerable number of false reactive results, satisfaction was high among participants. The project helped us to reach the target population, both in numbers of tests executed and in newly diagnosed HIV infections. Further optimization should be considered in the accuracy of the test, the functionalities of the website (including an online counseling tool), and in studying the cost effectiveness of the methodology.
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Affiliation(s)
- Tom Platteau
- Institute of Tropical Medicine, Department of Clinical Sciences, Antwerp, Belgium.
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Jespers V, Hardy L, Buvé A, Loos J, Tsoumaris A, Buyze J, Crucitti T. 004.5 The influence of sexual debut on selected vaginal, rectal and oral microbiota and vaginal inflammatory markers in belgian adolescent girls: a cohort study. Br J Vener Dis 2015. [DOI: 10.1136/sextrans-2015-052270.101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Abstract
The image shows a body map created by a young HIV-positive African woman living in Belgium. It was created as part of a body-mapping workshop with 10 sub-Saharan African migrants living with HIV. The short text provided with the image describes experiences and results of this workshop. The participants experienced body-mapping as a valuable tool in coping with HIV and it supported them in disclosing HIV to others.
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Affiliation(s)
| | - Jasna Loos
- Institute of Tropical Medicine, Department of Public Health, Antwerp, Belgium
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Loos J, Manirankunda L, Hendrickx K, Remmen R, Nöstlinger C. HIV testing in primary care: feasibility and acceptability of provider initiated HIV testing and counseling for sub-Saharan African migrants. AIDS Educ Prev 2014; 26:81-93. [PMID: 24450280 DOI: 10.1521/aeap.2014.26.1.81] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Provider-initiated HIV testing and counseling (PITC) is recommended to reduce late HIV diagnoses, common among Sub-Saharan African migrants (SAM) residing in Europe. Primary care represents an ideal entry point for PITC. To support Flemish general practitioners (GPs), we developed a culturally sensitive PITC tool. Over a 12-week period, 65 GPs implemented PITC to assess acceptability and feasibility of PITC. The qualitative evaluation showed high acceptability among physicians. Routine PITC was challenged by physicians' personal discomfort, assumptions of patients' sexual risk, perceived incoherence with reasons for consultation, and time pressure. The best opportunity for PITC was an indicated blood analysis for other medical reasons. Counseling skills improved during the implementation, but participants still advocated for reduced counseling requirements. PITC proved to be feasible in primary care settings, but the up-scaling requires a reformulation of counseling guidelines, a policy stipulating the role of GPs in the prevention-care continuum, and an investment in (continuous) training.
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Manirankunda L, Loos J, Debackaere P, Nöstlinger C. "It is not easy": challenges for provider-initiated HIV testing and counseling in Flanders, Belgium. AIDS Educ Prev 2012; 24:456-468. [PMID: 23016506 DOI: 10.1521/aeap.2012.24.5.456] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
This study identified physicians' HIV testing practices and their barriers toward implementing provider-initiated HIV testing and counseling (PITC) for Sub-Saharan African migrants (SAM) in Flanders, Belgium. In-depth interviews were conducted on a purposive sample of 20 physicians (ten GPs and ten internists). GPs performed mainly patient-initiated tests, while internists carried out tests based on disease indicators and risk behavior. For the most part, World Health Organization (WHO) guidelines were not followed. Study participants were not in favor of implementing PITC. Reasons included lack of information on the HIV epidemic among SAM, fear of stigmatizing patients, perceiving testing as unethical for undocumented patients, questionable relevance of pre-test counseling, lack of expertise in discussing sexuality, language barriers, lack of time, and the absence of a national or regional HIV testing policy. Implementing PITC will require appropriate training of service providers. Also, supporting policies should be developed with the participation of stakeholders encouraging "normalization" of HIV testing.
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Masquillier C, Wouters E, Loos J, Nöstlinger C. Measuring health-related quality of life of HIV-positive adolescents in resource-constrained settings. PLoS One 2012; 7:e40628. [PMID: 22815776 PMCID: PMC3398030 DOI: 10.1371/journal.pone.0040628] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Accepted: 06/11/2012] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Access to antiretroviral treatment among adolescents living with HIV (ALH) is increasing. Health-related quality of life (HRQOL) is relevant for monitoring the impact of the disease on both well-being and treatment outcomes. However, adequate screening tools to assess HRQOL in low-resource settings are scarce. This study aims to fill this research gap, by 1) assessing the psychometric properties and reliability of an Eastern African English version of a European HRQOL scale for adolescents (KIDSCREEN) and 2) determining which version of the KIDSCREEN (52-, 27- and 10-item version) is most suitable for low-resource settings. METHODS The KIDSCREEN was translated into Eastern African English, Luganda (Uganda) and Dholuo (Kenya) according to standard procedures. The reconciled version was administered in 2011 to ALH aged 13-17 in Kenya (n = 283) and Uganda (n = 299). All three KIDSCREEN versions were fitted to the data with confirmatory factor analysis (CFA). After comparison, the most suitable version was adapted based on the CFA outcomes utilizing the results of previous formative research. In order to develop a general HRQOL factor, a second-order measurement model was fitted to the data. RESULTS The CFA results showed that without adjustments, the KIDSCREEN cannot be used for measuring the HRQOL of HIV-positive adolescents. After comparison, the most suitable version for low-resource settings--the 27-item version--was adapted further. The introduction of a negative wording factor was required for the Dholuo model. The Dholuo (CFI: 0.93; RMSEA: 0.039) and the Luganda model (CFI: 0.90; RMSEA: 0.052) showed a good fit. All cronbach's alphas of the factors were 0.70 or above. The alpha value of the Dholuo and Lugandan HRQOL second-order factor was respectively 0.84 and 0.87. CONCLUSIONS The study showed that the adapted KIDSCREEN-27 is an adequate tool for measuring HRQOL in low-resource settings with high HIV prevalence.
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Affiliation(s)
- Caroline Masquillier
- Department of Sociology, Research Centre for Longitudinal and Life Course Studies (CELLO), University of Antwerp, Antwerp, Belgium.
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Stenzel O, Schmidt V, Hassfeld H, Thiedmann R, Koster LJA, Oosterhout SD, van Bavel SS, Wienk MM, Loos J, Janssen RAJ. Spatial modeling of the 3D morphology of hybrid polymer-ZnO solar cells, based on electron tomography data. Ann Appl Stat 2011. [DOI: 10.1214/11-aoas468] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Xue L, Li W, Hoffmann GG, Goossens JGP, Loos J, de With G. High Resolution Tip Enhanced Raman Mapping on Polymer Thin Films. ACTA ACUST UNITED AC 2011. [DOI: 10.1002/masy.201000132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Nöstlinger C, Nideröst S, Woo R, Platteau T, Loos J, Colebunders R, The Swiss HIV Cohort Study, The Eurosupport 5 Study Group. Mirror, mirror on the wall: the face of HIV + women in Europe today. AIDS Care 2010; 22:919-26. [DOI: 10.1080/09540121003758564] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- C. Nöstlinger
- a Department of Clinical Sciences , Prins Leopold Institute of Tropical Medicine , Antwerp , Belgium
| | - S. Nideröst
- b School of Social Work , University of Applied Sciences Northwestern Switzerland , Olten , Switzerland
| | - R. Woo
- a Department of Clinical Sciences , Prins Leopold Institute of Tropical Medicine , Antwerp , Belgium
| | - T. Platteau
- a Department of Clinical Sciences , Prins Leopold Institute of Tropical Medicine , Antwerp , Belgium
| | - J. Loos
- a Department of Clinical Sciences , Prins Leopold Institute of Tropical Medicine , Antwerp , Belgium
| | - R. Colebunders
- a Department of Clinical Sciences , Prins Leopold Institute of Tropical Medicine , Antwerp , Belgium
- c Faculty of Medicine , University of Antwerp , Antwerp , Belgium
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Manirankunda L, Loos J, Alou TA, Colebunders R, Nöstlinger C. "It's better not to know": perceived barriers to HIV voluntary counseling and testing among sub-Saharan African migrants in Belgium. AIDS Educ Prev 2009; 21:582-593. [PMID: 20030501 DOI: 10.1521/aeap.2009.21.6.582] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This study explored perceptions, needs, and barriers of sub-Saharan African migrants in relation to HIV voluntary counseling and testing (VCT). Using an inductive qualitative methodological approach, data were obtained from focus group discussions. Results showed that participants were in principle in favor of VCT. However, they indicated that barriers outweighed advantages. Such barriers included fear of positive test results and its related personal and social consequences, lack of information, lack of preventive health behavior, denial of HIV risk, and missed opportunities. Limited financial resources were only a concern for some subgroups like young people, asylum seekers, and recent migrants. This study identified multiple and intertwined barriers to VCT from a community perspective. In order to promote VCT, interventions such as raising awareness through culturally sensitive education should be adopted at community level. At level of service provision, provider initiated HIV testing including target group tailored counseling should be promoted.
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Abstract
To describe the interaction of molecular vibrations with electrons at a quantum dot contacted to metallic leads, we extend an analytical approach that we previously developed for the many-polaron problem. Our scheme is based on an incomplete variational Lang-Firsov transformation, combined with a perturbative calculation of the electron-phonon self-energy in the framework of generalized Matsubara functions. This allows us to describe the system at weak-to-strong coupling and intermediate-to-large phonon frequencies. We present results for the quantum dot spectral function and for the kinetic coefficient that characterizes the electron transport through the dot. With these results we critically examine the strengths and limitations of our approach, and discuss the properties of the molecular quantum dot in the context of polaron physics. We place particular emphasis on the importance of corrections to the concept of an anti-adiabatic dot polaron suggested by the complete Lang-Firsov transformation.
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Affiliation(s)
- J Loos
- Institute of Physics, Academy of Sciences of the Czech Republic, 16200 Prague, Czech Republic
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Loos J, Sourty E, Lu K, Freitag B, Tang D, Wall D. Electron tomography on micrometer-thick specimens with nanometer resolution. Nano Lett 2009; 9:1704-8. [PMID: 19281214 DOI: 10.1021/nl900395g] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Transmission electron microscopy (TEM) is a well-established technique to explore matter down to the atomic scale. TEM tomography methods have been developed to obtain volume information at the mesoscopic dimensions of devices or complex mixtures of multiphase objects with nanometer resolution, but these methods are in general only applicable to relatively thin specimens with a few hundred nanometer thickness at most. Here we introduce an approach based on scanning TEM (STEM) tomography that pushes the resolution in three dimensions down to a few nanometers for several micrometer ultrathick specimens using a conventional TEM with 300 kV accelerating voltage, and we demonstrate its versatility for materials research and nanotechnology.
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Affiliation(s)
- J Loos
- Laboratory of Materials and Interface Chemistry, Soft-Matter CryoTEM Research Unit, and Laboratory of Polymer Technology, Eindhoven University of Technology, Eindhoven, The Netherlands.
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Forcén P, Oriol L, Sánchez C, Alcalá R, Hvilsted S, Jankova K, Loos J. Synthesis, characterization and photoinduction of optical anisotropy in liquid crystalline diblock azo-copolymers. ACTA ACUST UNITED AC 2007. [DOI: 10.1002/pola.21954] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Alcock B, Cabrera NO, Barkoula NM, Loos J, Peijs T. Interfacial properties of highly oriented coextruded polypropylene tapes for the creation of recyclable all-polypropylene composites. J Appl Polym Sci 2007. [DOI: 10.1002/app.24588] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Chen Z, Brokken-Zijp JCM, Huinink HP, Loos J, de With G, Michels MAJ. Cross-Linked Epoxy Composites Filled with Intrinsically Conductive Phthalocyanine Nanocrystals. Influence of Filler Amount, Layer Thickness, and Cross-Linkers Used on the Percolation Threshold and Conductivity Level of the Composites. Macromolecules 2006. [DOI: 10.1021/ma052144+] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Klimov E, Li W, Yang X, Hoffmann GG, Loos J. Scanning Near-Field and Confocal Raman Microscopic Investigation of P3HT−PCBM Systems for Solar Cell Applications. Macromolecules 2006. [DOI: 10.1021/ma052590x] [Citation(s) in RCA: 130] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- E. Klimov
- Laboratory of Materials and Interface Chemistry and Dutch Polymer Institute, Eindhoven University of Technology, Eindhoven, The Netherlands; Department of Macromolecular Science, Fudan University, Shanghai, China; and Laboratory of Molecular and Polymer Spectroscopy, University of Duisburg-Essen, Essen, Germany
| | - W. Li
- Laboratory of Materials and Interface Chemistry and Dutch Polymer Institute, Eindhoven University of Technology, Eindhoven, The Netherlands; Department of Macromolecular Science, Fudan University, Shanghai, China; and Laboratory of Molecular and Polymer Spectroscopy, University of Duisburg-Essen, Essen, Germany
| | - X. Yang
- Laboratory of Materials and Interface Chemistry and Dutch Polymer Institute, Eindhoven University of Technology, Eindhoven, The Netherlands; Department of Macromolecular Science, Fudan University, Shanghai, China; and Laboratory of Molecular and Polymer Spectroscopy, University of Duisburg-Essen, Essen, Germany
| | - G. G. Hoffmann
- Laboratory of Materials and Interface Chemistry and Dutch Polymer Institute, Eindhoven University of Technology, Eindhoven, The Netherlands; Department of Macromolecular Science, Fudan University, Shanghai, China; and Laboratory of Molecular and Polymer Spectroscopy, University of Duisburg-Essen, Essen, Germany
| | - J. Loos
- Laboratory of Materials and Interface Chemistry and Dutch Polymer Institute, Eindhoven University of Technology, Eindhoven, The Netherlands; Department of Macromolecular Science, Fudan University, Shanghai, China; and Laboratory of Molecular and Polymer Spectroscopy, University of Duisburg-Essen, Essen, Germany
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Wimmer MA, Nassutt R, Sprecher C, Loos J, Täger G, Fischer A. Investigation on stick phenomena in metal-on-metal hip joints after resting periods. Proc Inst Mech Eng H 2006; 220:219-27. [PMID: 16669389 DOI: 10.1243/09544119jeim117] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Insufficient understanding of tribological behaviour in total joint arthroplasty is considered as one of the reasons for prosthesis failure. Contrary to the continuous motion input profiles of hip simulators, human locomotion contains motion interruptions. These occurring resting periods can cause stick phenomena in metal-on-metal hip joints. The aim of the present study was to investigate the tribological sensitivity of all-metal bearings to motion interruptions on in vitro test specimens and retrieved implants. Friction and wear with and without resting periods were quantified. Unlike the metal-on-polyethylene joints, the static friction of metal-on-metal joints increased up to μs = 0.3 with rest, while wear appeared to be unaffected. This effect is caused by the interlocking of firmly adhered carbon layers, which were generated from the protein-containing lubricant through tribochemical reactions. Since more than 80 per cent of the retrieved implants exhibited macroscopically visible carbon layers, the increase in friction presumably also occurs under physiological conditions, which is then transferred to the bone-implant interface. These recurrent tangential stress peaks should be considered for the design features of the cup-bone interface, in particular when larger-sized implant heads are used.
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Affiliation(s)
- M A Wimmer
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois 60612, USA.
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Alexeev A, Loos J, Koetse MM. Nanoscale electrical characterization of semiconducting polymer blends by conductive atomic force microscopy (C-AFM). Ultramicroscopy 2006; 106:191-9. [PMID: 16125322 DOI: 10.1016/j.ultramic.2005.07.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2005] [Revised: 07/08/2005] [Accepted: 07/13/2005] [Indexed: 10/25/2022]
Abstract
For the first time local electrical characteristics of a blend of two semiconducting polymers were studied with conductive atomic force microscopy (C-AFM). The investigated mixture is potentially interesting as the active layer in plastic photovoltaic devices. Besides conventional topography analysis of morphology and phase separation, the internal structure of the active layer was investigated by observing the current distribution with nanoscale spatial resolution. Similar to force spectroscopy, current imaging spectroscopy was performed during scanning the sample surface. Different types of current-voltage (I-V) characteristics were extracted from the array of spectroscopic data obtained from each point of the scans, and local heterogeneities of the electric characteristic were determined and discussed.
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Affiliation(s)
- A Alexeev
- Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
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Ma Y, Agarwal U, Yang X, Zheng X, Loos J, Hendrix M, van Asselen O, Lemstra P. Nanoscale fibrillar crystals of PET from dilute quiescent solution. POLYMER 2005. [DOI: 10.1016/j.polymer.2005.06.065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Smit M, Severn JR, Zheng X, Loos J, Chadwick JC. Metallocene-catalyzed olefin polymerization using magnesium chloride-supported borate activators. J Appl Polym Sci 2005. [DOI: 10.1002/app.22449] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Loos J, Lemstra PJ, van Kimmenade EME, Niemantsverdriet JW, Höhne GWH, Thüne PC. Nascent morphology of polyethylene polymerized on flat model catalysts. POLYM INT 2004. [DOI: 10.1002/pi.1564] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Ming W, Tian M, van de Grampel RD, Melis F, Jia X, Loos J, van der Linde R. Low Surface Energy Polymeric Films from Solventless Liquid Oligoesters and Partially Fluorinated Isocyanates. Macromolecules 2002. [DOI: 10.1021/ma020650i] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- W. Ming
- Laboratory of Coatings Technology and Dutch Polymer Institute, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands, and Polymer Science and Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003
| | - M. Tian
- Laboratory of Coatings Technology and Dutch Polymer Institute, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands, and Polymer Science and Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003
| | - R. D. van de Grampel
- Laboratory of Coatings Technology and Dutch Polymer Institute, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands, and Polymer Science and Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003
| | - F. Melis
- Laboratory of Coatings Technology and Dutch Polymer Institute, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands, and Polymer Science and Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003
| | - X. Jia
- Laboratory of Coatings Technology and Dutch Polymer Institute, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands, and Polymer Science and Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003
| | - J. Loos
- Laboratory of Coatings Technology and Dutch Polymer Institute, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands, and Polymer Science and Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003
| | - R. van der Linde
- Laboratory of Coatings Technology and Dutch Polymer Institute, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands, and Polymer Science and Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003
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Kaminsky W, Arrowsmith D, Laban A, Lemstra PJ, Loos J, Weingarten U. The Influence of the Polymerization Process on the Product Properties of Metallocene-Polypropene. Chem Eng Technol 2001. [DOI: 10.1002/1521-4125(200111)24:11<1124::aid-ceat1124>3.0.co;2-v] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Kaminsky W, Arrowsmith D, Laban A, Lemstra PJ, Loos J, Weingarten U. Einfluss der Polymerisationsverfahren auf die Produkteigenschaften von Metallocen-Polypropen. CHEM-ING-TECH 2001. [DOI: 10.1002/1522-2640(200107)73:7<857::aid-cite857>3.0.co;2-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Schröder D, Loos J, Schwarz H, Thissen R, Dutuit O. Gas-phase properties and fragmentation behavior of cationic, dinuclear iron chloride clusters Fe(2)Cl(n)()(+) (n = 1-6). Inorg Chem 2001; 40:3161-9. [PMID: 11399188 DOI: 10.1021/ic0100020] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Sector-field mass spectrometry is used to probe the fragmentation patterns of cationic dinuclear iron chloride clusters Fe(2)Cl(n)()(+) (n = 1-6). For the chlorine-rich, high-valent Fe(2)Cl(n)()(+) ions (n = 4-6), losses of atomic and molecular chlorine prevail in the unimolecular and collision-induced dissociation patterns. Instead, the chlorine deficient, formally low-valent Fe(2)Cl(n)()(+) clusters (n = 1-3) preferentially undergo unimolecular degradation to mononuclear FeCl(m)()(+) ions. In addition, photoionization is used to determine IE(Fe(2)Cl(6)) = 10.85 +/- 0.05 eV along with appearance energy measurements for the production of Fe(2)Cl(5)(+) and Fe(2)Cl(4)(+) cations from iron(III) chloride vapor. The combination of the experimental results allows an evaluation of some of the thermochemical properties of the dinuclear Fe(2)Cl(n)()(+) cations: e.g., Delta(f)H(Fe(2)Cl(+)) = 232 +/- 15 kcal/mol, Delta(f)H(Fe(2)Cl(2)(+)) = 167 +/- 4 kcal/mol, Delta(f)H(Fe(2)Cl(3)(+)) = 139 +/- 4 kcal/mol, Delta(f)H(Fe(2)Cl(4)(+)) = 113 +/- 4 kcal/mol, Delta(f)H(Fe(2)Cl(5)(+)) = 79 +/- 5 kcal/mol, and Delta(f)H(Fe(2)Cl(6)(+)) = 93 +/- 2 kcal/mol. The analysis of the data suggests that structural effects are more important than the formal valency of iron as far as the Fe-Cl bond strengths in the Fe(2)Cl(n)()(+) ions are concerned.
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Affiliation(s)
- D Schröder
- Institut für Chemie der Technischen Universität Berlin, Strasse des 17. Juni 135, D-10623 Berlin, Germany
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Affiliation(s)
- J. Loos
- Dutch Polymer Institute and Schuit Institute of Catalysis, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - P. C. Thüne
- Dutch Polymer Institute and Schuit Institute of Catalysis, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - J. W. Niemantsverdriet
- Dutch Polymer Institute and Schuit Institute of Catalysis, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - P. J. Lemstra
- Dutch Polymer Institute and Schuit Institute of Catalysis, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
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Wimmer MA, Andriacchi TP, Natarajan RN, Loos J, Karlhuber M, Petermann J, Schneider E, Rosenberg AG. A striated pattern of wear in ultrahigh-molecular-weight polyethylene components of Miller-Galante total knee arthroplasty. J Arthroplasty 1998; 13:8-16. [PMID: 9493532 DOI: 10.1016/s0883-5403(98)90069-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Wear of the polyethylene tibial components is a potential cause of failure in total knee arthroplasty. In addition to pitting, burnishing, and scratching, subtle striations on the bearing portion of the tibial surface have been observed in components retrieved relatively early after implantation. The striated pattern most typically occurred in areas centrally located within the articulating surface. The striations were anteroposterior directed and were identified as local cold flow at the surface. There was a strong correlation between the medial and lateral striated areas, suggesting that these patterns are related to cyclic rolling of the knee. The general characteristics and alignment of the striations could be attributed to the compressive and tractive forces occurring during femoral rollback. For the clinician, these results suggest that kinematics, as well as contact stress, should be considered when evaluating wear of polyethylene components.
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Affiliation(s)
- M A Wimmer
- Biomechanics Section, Technical University of Hamburg-Harburg, Hamburg, Germany
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