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In this investigation, our primary objective is to explore the structural, morphological, and electrical characteristics of Bi0.75Ba0.25(FeMn)0.5O3 ceramic material synthesized by the sol-gel method. The prepared sample underwent synthesis through the conventional sol-gel technique. Examination through X-ray diffraction (XRD) unveiled a well-defined rhombohedral structure within the R3´C space group. Moreover, to evaluate the purity and nano-grain morphology, we utilized energy dispersive spectroscopy (EDX) and scanning electron microscopy (SEM). Electrical assessments were carried out over a frequency span of 100 Hz to 1 MHz and temperatures ranging from 200 to 340 K. Employing the correlated barrier hopping (CBH) model, we analyzed the AC conductivity of our specimen. The activation energy, determined from both DC conductivity and impedance spectra, demonstrated close correspondence, suggesting that both conductivity and r laxation processes are influenced by similar factors. Notably, the dielectric properties hold significant importance, potentially rendering our sample suitable for electronic applications. Furthermore, we calculated thermodynamic parameters, such as enthalpy (ΔH), entropy change (ΔS), and free energy of activation (ΔF), offering deeper insights into the material's behavior and conductivity mechanisms.
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BACKGROUND: The World Health Organization (WHO) recommends that HIV treatment scale-up is accompanied by a robust assessment of drug resistance emergence and transmission. The WHO HIV Drug Resistance (HIVDR) monitoring and surveillance strategy includes HIVDR testing in adults both initiating and receiving antiretroviral therapy (ART). Due to limited information about HIVDR in Mozambique, we conducted two nationally representative surveys of adults initiating and receiving first-line ART regimes to better inform the HIV program. METHODS: We carried out a cross-sectional study between March 2017 and December 2019. Adults (older than 15 years) living with HIV (PLHIV) initiating ART or receiving first-line ART for between 9-15 months at 25 health facilities across all eleven provinces in Mozambique were included. Genotypic HIVDR was assessed on dried blood spots (DBS) when viral loads were ≥ 1000 copies/ml. Genotypic resistance for non-nucleoside reverse transcriptase inhibitors (NNRTIs), nucleoside reverse transcriptase inhibitors (NRTIs), and protease inhibitors (PIs) was determined using the Stanford HIV database algorithm 9.5 and calibrated population resistance tool 8.1. RESULTS: Of 828 participants -enrolled, viral load (VL) testing was performed on 408 initiators and 409 ART experienced. Unsuppressed VL was found in 68.1% 419 initiators and 18.8% (77/409) of the ART experienced. Of the 278 initiators and 70 ART experienced who underwent sequencing, 51.7% (144/278) and 75.7% (53/70) were sequenced successfully. Among the new initiators, pretreatment drug resistance (PDR) for NNRTI and PI was found in 16.0% (23/144) and 1.4% (2/144) of the participants, respectively. Acquired drug resistance (ADR) was found in 56.5% (30/53) of the ART-experienced participants of whom 24.5% (13/53) were resistant to both NRTI and NNRTI. CONCLUSION: High rates of PDR and ADR for NNRTI and ADR for NRTI were observed in our study. These findings support the replacement of NNRTIs with dolutegravir (DTG) but high levels of NRTI resistance in highly treatment-experienced individuals still require attention when transitioning to new regimens. Moreover, the study underlines the need for routine VL testing and HIVDR surveillance to improve treatment management strategies.
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Fármacos Anti-VIH , Farmacorresistencia Viral , Infecciones por VIH , VIH-1 , Compuestos Heterocíclicos con 3 Anillos , Lamivudine , Oxazinas , Piridonas , Tenofovir , Humanos , Mozambique/epidemiología , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , Masculino , Farmacorresistencia Viral/genética , Femenino , Adulto , Estudios Transversales , VIH-1/efectos de los fármacos , VIH-1/genética , Fármacos Anti-VIH/uso terapéutico , Piridonas/uso terapéutico , Persona de Mediana Edad , Lamivudine/uso terapéutico , Tenofovir/uso terapéutico , Compuestos Heterocíclicos con 3 Anillos/uso terapéutico , Oxazinas/uso terapéutico , Adulto Joven , Piperazinas/uso terapéutico , Adolescente , Carga Viral/efectos de los fármacos , GenotipoRESUMEN
The aging population and increasing incidence of trauma among younger age groups have heightened the increasing demand for reliable implant materials. Effective implant materials must demonstrate rapid osseointegration and strong antibacterial properties to ensure optimal patient outcomes and decrease the chance of implant rejection. This study aims to enhance the bone-implant interface by utilizing 45S5 bioglass modified with various concentrations of Fe3O4 as a coating material. The effect of the insertion of Fe3O4 into the bioglass structure was studied using Raman spectroscopy which shows that with the increase in Fe3O4 concentration, new vibration bands associated with Fe-related structural units appeared within the sample. The bioactivity of the prepared glasses was evaluated using immersion tests in simulated body fluid, revealing the formation of a calcium phosphate-rich layer within 24 h on the samples, indicating their potential for enhanced tissue integration. However, the sample modified with 8 mol% of Fe3O4 showed low reactivity, developing a calcium phosphate-rich layer within 96 h. All the bioglasses showed antibacterial activity against the Gram-positive and Gram-negative bacteria. The modified bioglass did not present significant antibacterial properties compared to the bioglass base.
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Background: Adverse childhood experiences (ACEs) can have debilitating effects on child well-being, with consequences persisting into adulthood. Most ACE studies have been conducted in high-income countries and show a graded relationship between multiple ACE exposures and adverse health outcomes. Less is known about the types and burden of ACEs in sub-Saharan Africa (SSA). Objective: To estimate the pooled prevalence of six individual and cumulative ACE exposures (physical, sexual, and emotional violence; orphanhood; witnessing interparental and community violence) and assess their association with mental health outcomes, substance use, and violence perpetration among young adults in SSA. Participants and setting: Aggregate data from the Violence Against Children and Youth Survey (VACS) in Cote d'Ivoire 2018, Kenya 2019, Lesotho 2018, Mozambique 2019, and Namibia 2019 included a sample of 11,498 young adults aged 18-24 years. Methods: Cumulative ACEs were defined by an integer count of the total number of individual ACEs (0 to 6). Weighted prevalence and adjusted odds ratios were estimated. Result: ACEs prevalence ranged from 7.8% (emotional violence) to 55.0% (witnessing community violence). Strong graded relationships between cumulative ACE exposure and all study outcomes for both males and females were observed. Among females, witnessing interparental violence was the only individual ACE risk factor significantly associated with increased odds of substance use; among males, emotional violence was significantly associated with all outcomes. Conclusion: ACEs are associated with adverse mental health, substance use, and violence perpetration in SSA. Gender-specific and culturally sensitive intervention strategies are needed to effectively mitigate ACEs in this population.
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Experiencias Adversas de la Infancia , Trastornos Relacionados con Sustancias , Humanos , Masculino , Femenino , Adulto Joven , Experiencias Adversas de la Infancia/estadística & datos numéricos , Adolescente , Trastornos Relacionados con Sustancias/epidemiología , Trastornos Relacionados con Sustancias/psicología , África del Sur del Sahara/epidemiología , Violencia/estadística & datos numéricos , Violencia/psicología , Salud Mental , Prevalencia , NiñoRESUMEN
Biphasic calcium phosphate (BCP), consisting of bioceramics such as HAp + ß-TCP and Ca10(PO4)6(OH)2 + Ca3(PO4)2, is a popular choice for optimizing performance due to its superior biological reabsorption and osseointegration. In this study, BCP was produced by calcining the bones of tilapia fish (Oreochromis niloticus) reared in net cages and slaughtered at an age ranging from 15 to 420 days. The bones were cleaned and dried, calcined at 900 °C for 8 h, and then subjected to high-energy grinding for 3 h to produce BCP powders. After the calcination process, the crystalline phase's hydroxyapatite (HAp) and/or beta-tricalcium phosphate (ß-TCP) were present in the composition of the bioceramic. The age-dependent variation in phase composition was confirmed by complementary vibrational spectroscopy techniques, revealing characteristic peaks and bands of the bioceramic. This variation was marked by an increase in HAp phase and a decrease in ß-TCP phase. Thermogravimetric Analysis (TGA) and Differential Thermal Analysis (DTA) from 25 to 1400 °C showed the characteristic mass losses of the material, with a greater loss observed for younger fish, indicating the complete removal of organic components at temperatures above 600 °C. Comparison of the results obtained by X-Ray Diffraction (XRD) and Rietveld refinement with Raman spectroscopy showed excellent agreement. These results showed that with temperature and environment control and adequate fish feeding, it is possible to achieve the desired amounts of each phase by choosing the ideal age of the fish. This bioceramic enables precise measurement of HAp and ß-TCP concentrations and Ca/P molar ratio, suitable for medical orthopedics and dentistry.
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Huesos , Cerámica , Espectrometría Raman , Animales , Cerámica/química , Huesos/química , Tilapia/metabolismo , Difracción de Rayos X , Hidroxiapatitas/química , Espectroscopía Infrarroja por Transformada de Fourier , Fosfatos de Calcio/química , TermogravimetríaRESUMEN
In recent decades, the requirements for implantable medical devices have increased, but the risks of implant rejection still exist. These issues are primarily associated with poor osseointegration, leading to biofilm formation on the implant surface. This study focuses on addressing these issues by developing a biomaterial for implant coatings. 45S5 bioglass® has been widely used in tissue engineering due to its ability to form a hydroxyapatite layer, ensuring a strong bond between the hard tissue and the bioglass. In this context, 45S5 bioglasses®, modified by the incorporation of different amounts of copper oxide, from 0 to 8 mol%, were synthesized by the melt-quenching technique. The incorporation of Cu ions did not show a significant change in the glass structure. Since the bioglass exhibited the capacity for being polarized, thereby promoting the osseointegration effectiveness, the electrical properties of the prepared samples were studied using the impedance spectroscopy method, in the frequency range of 102-106 Hz and temperature range of 200-400 K. The effects of CuO on charge transport mobility were investigated. Additionally, the bioactivity of the modified bioglasses was evaluated through immersion tests in simulated body fluid. The results revealed the initiation of a Ca-P-rich layer formation on the surface within 24 h, indicating the potential of the bioglasses to enhance the bone regeneration process.
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45S5 Bioglass has been widely used in regenerative medicine due to its ability to dissolve when inserted into the body. Its typically amorphous structure allows for an ideal dissolution rate for the formation of the hydroxyapatite layer, which is important for the development of new bone. This bioactive capacity can also be controlled by adding other oxides (e.g., SrO, ZnO, and MgO) to the 45S5 Bioglass network or by storing electrical charge. Ions such as zinc, magnesium, and strontium allow for specific biological responses to be added, such as antibacterial action and the ability to increase the rate of osteoblast proliferation. The charge storage capacity allows for a higher rate of bioactivity to be achieved, allowing for faster attachment to the host bone, decreasing the patient's recovery time. Therefore, it is necessary to understand the variation in the structure of the bioglass with regard to the amount of non-bridging oxygens (NBOs), which is important for the bioactivity rate not to be compromised, and also its influence on the electrical behavior relevant to its potential as electrical charge storage. Thus, several bioactive glass compositions were synthesized based on the 45S5 Bioglass formulation with the addition of various concentrations (0.25, 0.5, 1, and 2, mol%) of zinc, strontium, or magnesium oxides. The influence of the insertion of these oxides on the network was evaluated by studying the amount of NBOs using Raman spectroscopy and their implication on the electrical behavior. Electrical characterization was performed in ac (alternating current) and dc (direct current) regimes.
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BACKGROUND: Multiple adverse childhood experiences (ACEs) are associated with poor sexual and mental health outcomes in low- and middle-income countries (LMICs). Less well understood is how discrete and gendered clustering of ACEs may influence health. OBJECTIVE: To assess how multiple ACEs co-occur and how dominant patterns of co-occurrence are associated with mental distress, substance use, and sexual risk behaviors among young women and men in Sub-Saharan Africa. PARTICIPANTS AND SETTING: We used pooled data of young men and women aged 19-24 from comparable, nationally representative Violence Against Children and Youth Surveys (VACS) conducted in Cote d'Ivoire, Kenya, Lesotho, Mozambique, and Namibia (nf = 7183; nm = 2207). METHODS: We estimated sex-disaggregated latent classes of six ACEs among young women and men. We ran Bolck-Croon-Hagenaars (BCH) distal outcome analysis to test the sex-stratified relationships between ACEs latent classes and health outcomes. RESULTS: A six class solution best fit the female data. Classes included witnessing violence and experiencing physical violence (PV); experiencing PV; high ACEs; witnessing community violence; orphanhood; and low ACEs exposure. Among males, the best-fitting three-class solution included experiencing PV and witnessing community violence; high ACEs; and low ACEs exposure. Membership in the high ACEs class was associated with mental distress among females and males, and substance use among males. No differences in sexual risk behavior were identified by class membership among either females or males. CONCLUSIONS: Discrete clusters of co-occurring ACEs are associated with elevated odds of mental distress among females, and mental distress and substance use among males. Preventing ACEs may improve mental health among young women and men in LMICs in Sub-Saharan Africa.
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Experiencias Adversas de la Infancia , Trastornos Relacionados con Sustancias , Masculino , Adolescente , Niño , Humanos , Femenino , Conducta Sexual , Trastornos Relacionados con Sustancias/epidemiología , Trastornos Relacionados con Sustancias/psicología , Violencia , Asunción de RiesgosRESUMEN
BACKGROUND: Adverse Childhood Experiences (ACEs) are associated with poor mental health outcomes and risk-taking behaviors. Positive childhood experiences (PCEs) may mitigate these negative impacts. OBJECTIVE: This study 1) assessed the associations between ACEs and negative health outcomes and risk-taking behaviors among young adults, and 2) evaluated whether - and which - PCEs moderate the association between ACEs and these outcomes in sub-Saharan Africa. METHODS: This multi-country analysis combined cross-sectional representative survey data from young adults, ages 18-24 years, from the 2019 Kenya, 2018 Lesotho, 2019 Mozambique, and 2019 Namibia Violence Against Children and Youth Surveys. The association between experiencing any ACEs and each health outcome was assessed using Wald's chi-square tests. Multivariable logistic regression analyses assessed the association between each PCE and each outcome of interest. RESULTS: Females who experienced any ACEs had higher odds of experiencing moderate to severe mental distress (aOR = 2.7, 95%CI: 1.9, 3.9). Males who experienced any ACEs had higher odds of experiencing suicidal/self-harm behaviors (aOR = 6.7, 95%CI: 2.8, 16.0) and substance use (aOR = 2.5, 95%CI: 1.4, 4.2). In females, strong mother-child relationship was protective against moderate to severe mental distress (aOR = 0.7, 95%CI: 0.6, 0.9), suicidal/self-harm behaviors (aOR = 0.6, 95%CI: 0.4, 0.9), and substance use (aOR = 0.6, 95%CI: 0.4, 0.9). For males, a strong mother-child relationship was protective against suicidal/self-harm behaviors (aOR = 0.5, 95%CI: 0.2, 0.9), and a strong father-child relationship was protective against suicidal/self-harm behaviors (aOR = 0.4, 95%CI: 0.2, 0.7) and substance use (aOR = 0.6, 95%CI: 0.4, 0.8). CONCLUSIONS: Strong parenting programs may likely play an important role in improving the psychosocial health of young adults.
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Experiencias Adversas de la Infancia , Trastornos Relacionados con Sustancias , Masculino , Femenino , Adolescente , Adulto Joven , Humanos , Salud Mental , Responsabilidad Parental , Estudios Transversales , KeniaRESUMEN
BACKGROUND: Violence against boys and men is widely under-reported. Boys and men face unique and gendered barriers to accessing services following experiences of violence. PARTICIPANTS AND SETTING: The study is a secondary data analysis of five nationally representative population-based Violence Against Children and Youth Surveys (VACS) conducted in Kenya (2019), Côte d'Ivoire (2018), Lesotho (2018), Mozambique (2019), and Namibia (2019). Analysis was limited to males between 18 and 24 years who experienced lifetime physical or sexual violence. OBJECTIVE AND METHODS: We analyzed the association between positive and adverse childhood experiences (PCEs and ACEs), and seeking post-violence services among males using bivariate chi-squared tests and multivariable logistic regression. RESULTS: 8.02 % (5.55-10.50 %) of male victims between the ages of 18 and 24 sought services for any lifetime physical or sexual violence. Witnessing interparental violence and experiencing death of one or both parents were each associated with increased odds of having sought post-violence services (aOR 2.43; 95 % CI: 1.25-4.79; aOR 2.27; 95 % CI: 1.14-4.50), controlling for education, violence frequency, and violence type. High parental monitoring was associated with increased odds of service seeking (aOR 1.79; 95 % CI: 1.02-3.16), while strong father-child relationship was associated with lower odds (aOR 0.45; 95 % CI: 0.23-0.89). CONCLUSION: These findings contribute to limited research on service-seeking behaviors among men and boys. While some parent-youth relationship factors were associated with higher odds of service-seeking, the outcome remained rare. Age and gender-related barriers should be addressed where post-violence care services are offered.
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Experiencias Adversas de la Infancia , Delitos Sexuales , Adolescente , Humanos , Masculino , Adulto Joven , Adulto , Violencia , Conducta Sexual , Côte d'IvoireRESUMEN
BACKGROUND: Adverse Childhood Experiences are traumatic events early in life and have been associated with significant negative health outcomes. OBJECTIVE: To estimate the prevalence of ACEs in five low- and middle-income sub-Saharan African countries. PARTICIPANTS AND SETTING: Nationally representative data from the Cote d'Ivoire (2018), Kenya (2019), Lesotho (2018), Mozambique (2019), and Namibia (2019) Violence Against Children and Youth Surveys (VACS) were used. Analyses were restricted to youth ages 18-24 years (n = 8766 females and 2732 males). METHODS: VACS data were analyzed to generate sex-stratified weighted prevalence of individual ACEs (including sexual, physical, and emotional violence; witnessing interparental violence and violence in the community; and orphanhood) and aggregate ACEs (total ACEs; 0, 1-2, and 3 or more), for each country and combined. RESULTS: The most common type of ACEs among both females and males was witnessing physical violence (males: 55.0 % [95 % CI: 51.1-58.8] and females: 37.2 % [95 % CI = 34.3-40.1]) followed by experiencing physical violence (males: 49.7 % [95 % CI = 45.5-53.9] and in females: 36.5 % [95 % CI = 33.8-39.2]). Prevalence of sexual violence was significantly higher in females than in males (16.0 % [95 % CI = 13.9-18.2] vs 8.3 % [95 % CI = 7.0-9.8]; p < 0.001). About 72 % of females and 82 % of males have experienced at least one form of ACE with 20 % of females and 24.2 % of males experiencing 3 or more ACEs. CONCLUSION: This study demonstrated that majority of the children in countries in sub-Saharan Africa have experienced multiple ACEs in their lifetime. Understanding the extent of the problem will help design early interventions to reduce childhood exposure to ACEs or mitigate against the harmful impact of ACEs.
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Experiencias Adversas de la Infancia , Delitos Sexuales , Masculino , Niño , Femenino , Humanos , Adolescente , Prevalencia , Violencia , Delitos Sexuales/psicología , KeniaRESUMEN
BACKGROUND: Parental absence in childhood has been associated with multiple negative consequences, such as depression and anxiety in young adulthood. OBJECTIVE: To assess whether parental absence for six months or more in childhood is associated with poor mental health and substance use in young adulthood and whether parental absence accounts for additional variance beyond those explained by other adverse childhood experiences (ACEs) among youth in sub-Saharan Africa. PARTICIPANTS AND SETTINGS: We used combined Violence Against Children and Youth Survey (VACS) data from Cote d'Ivoire (2018), Lesotho (2018), Kenya (2019), Namibia (2019), and Mozambique (2019). Analyses were restricted to 18-24-year-olds (nf = 7699; nm = 2482). METHODS: We used logistic regression to examine sex-stratified relationships between parental absence in childhood (defined as biological mother or father being away for six months or more before age 18) and mental health problems and substance use and whether parental absence explained additional variance beyond those explained by other ACEs. RESULTS: In sub-Saharan Africa, parental absence in childhood was common (30.5 % in females and 25.1 % in males), significantly associated with poor mental health and substance use among females and males and accounted for additional variance beyond those explained by conventional ACEs. For example, after controlling for study covariates and other ACEs, females who experienced any parental absence had 1.52 (95 % CI = 1.02-2.26) higher odds of experiencing moderate/serious psychological distress compared with those who did not. CONCLUSION: The observed association between parental absence and poor mental health suggests that this experience has significant adverse consequences and merits consideration as an ACE.
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Experiencias Adversas de la Infancia , Trastornos Relacionados con Sustancias , Masculino , Niño , Femenino , Adolescente , Humanos , Adulto Joven , Adulto , Violencia , Salud Mental , Trastornos Relacionados con Sustancias/epidemiología , Trastornos Relacionados con Sustancias/psicología , PadresRESUMEN
BACKGROUND: Adverse childhood experiences (ACEs) have been shown to have negative, lasting effects on health including increasing the likelihood of engaging in sexual risk behaviors. OBJECTIVE: This study aimed to identify associations between exposures to ACEs and sexual risk behaviors and HIV service utilization among young people. PARTICIPANTS AND SETTING: A sample of 8023 sexually active young people (19-24 year olds) from five sub-Saharan African countries participated Violence Against Children and Youth Surveys (VACS). METHODS: Descriptive analysis of demographic variables, individual ACEs, cumulative ACEs, sexual risk behaviors, HIV testing, antiretroviral treatment (ART) and Antenatal Care (ANC) attendance were completed. Bivariate and multivariable logistic regression analyses were conducted to assess the associations between both individual and cumulative ACEs, sexual HIV risk behaviors, and service utilization while controlling for important covariates such as demographic, having ever been pregnant, had an STI, and used contraception. RESULTS: Exposure to three or more ACEs was higher among males (26.1 %) compared to females (21.3 %); p = 0.003. The most prominent sexual risk behavior for females was having sexual partners who were at least 5 years older (45.7 % compared to males 3.7 %; p < 0.0001) whereas in males it was no or infrequent condom use (45.3 % compared to females 30.1 %; p < 0.0001). Males and females exposed to childhood sexual violence had seven and four times the odds of engaging in transactional sex (aOR = 7.34, 95 % CI: [3.5-15.0]) and (aOR =3.75, 95 % CI: [2.3-6.2], respectively. Females exposed to three or more ACEs were four times more likely to engage in transactional sex (aOR = 4.85, 95 %, CI: [1.6-14.4]) compared to those who did not experience any ACEs. Males exposed to three or more ACEs were two times more likely to engage in early sexual debut (aOR = 2.2, 95 % CI: [1.3-3.4]),]) compared to those who did not experience any ACEs. Females who had witnessed IPV or violence in the community had significantly higher odds of getting tested for HIV (aOR = 2.16, 95 % CI: [1.63-2.87]) and (aOR = 1.36, 95 % CI: [1.03-1.81]), respectively. CONCLUSIONS: This study demonstrated that experiencing ACEs during childhood is associated with higher HIV risk behaviors in sub-Saharan Africa (SSA) with unique differences between males and females.
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Experiencias Adversas de la Infancia , Infecciones por VIH , Delitos Sexuales , Masculino , Adolescente , Niño , Humanos , Femenino , Embarazo , Conducta Sexual , Infecciones por VIH/epidemiología , Asunción de RiesgosRESUMEN
An investigation was carried out to examine the use of national Xpert MTB/RIF data (2013-2017) and GIS technology for MTB/RIF surveillance in South Africa. The aim was to exhibit the potential of using molecular diagnostics for TB surveillance across the country. The variables analysed include Mycobacterium tuberculosis (Mtb) positivity, the mycobacterial proportion of rifampicin-resistant Mtb (RIF), and probe frequency. The summary statistics of these variables were generated and aggregated at the facility and municipal level. The spatial distribution patterns of the indicators across municipalities were determined using the Moran's I and Getis Ord (Gi) statistics. A case-control study was conducted to investigate factors associated with a high mycobacterial load. Logistic regression was used to analyse this study's results. There was striking spatial heterogeneity in the distribution of Mtb and RIF across South Africa. The median patient age, urban setting classification, and number of health care workers were found to be associated with the mycobacterial load. This study illustrates the potential of using data generated from molecular diagnostics in combination with GIS technology for Mtb surveillance in South Africa. Spatially targeted interventions can be implemented in areas where high-burden Mtb persists.
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The non-surgical treatments are being required to reconstruct damaged tissue, prioritizing our body's natural healing process. Thus, the use of bioactive materials such as bioactive glass has been studied to support the repair and restoration of hard and soft tissue. Thus, in this work Bioglass 45S5 was developed, adding 1 and 2%mol of SrO or MgO and the physical and biological properties were evaluated. The addition of MgO and SrO at the studied concentrations promoted the slight increase in non-bridging oxygens number, observed through the temperature shift in phase transitions to lower values compared to Bioglass 45S5. The insertion of the ions also showed a positive effect on Saos-2 cell viability, decreasing the cytotoxic of Bioglass 45S5. Besides the Ca/P ratio on the pellets surface demonstrating no evidence of higher reactivity between Bioglass 45S5 and Bioglass with Sr and Mg, micrographs show that at 24 h the Ca/P rich layer is denser than in Bioglass 45S5 after the contact with simulated body fluid. The samples with Sr and Mg show a higher antibacterial effect compared to Bioglass 45S5. The addition of the studied ions may benefit the biological response of Bioglass 45S5 in dental applications as scaffolds or coatings.
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This study seeks to describe the rollout and current state of South Africa's GeneXpert molecular diagnostic program for tuberculosis (TB). Xpert MTB/RIF was introduced in 2011 with a subsequent expansion to include extra-pulmonary and paediatric testing, followed by Xpert MTB/RIF Ultra in 2017. Through a centralised laboratory information system and the use of a standardised platform for more than a decade, over 23 million tests were analysed, describing the numbers tested, Mycobacterium tuberculosis complex detection, rifampin resistance, and the unsuccessful test rates. The stratification by province, specimen type, age, and sex identified significant heterogeneity across the program and highlighted testing gaps for men, low detection yield for paediatric pulmonary TB, and the effects of inadequate specimen quality on the detection rate. The insights gained from these data can aid in the monitoring of interventions in support of the national TB program beyond laboratory operational aspects.
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BACKGROUND: Coronavirus disease (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first reported in Wuhan, China. Due to the rapid spread globally, it was declared a pandemic in March 2020. Social distancing and lockdown measures were introduced to limit transmission. These strategies could potentially impact the diagnosis and treatment of patients with advanced HIV who are susceptible to secondary infections like cryptococcal disease. In South Africa, reflexed cryptococcal antigenaemia (CrAg) testing and pre-emptive antifungal treatment are recommended preceding antiretroviral therapy initiation for patients with a CD4<100 cells/µl. This study aimed to assess the impact of COVID-19 on CrAg testing in South Africa. METHODS: Specimen-level data was extracted for individuals ≥15 years from the National Health Laboratory Services repository for calendar years 2018 to 2021. Test volumes and CrAg positivity were assessed at national and provincial levels, by age category and gender. The percentage change in annual and monthly CrAg test volumes for 2020 and 2021 (during lockdown levels) are compared to data reported for 2018. The monthly median CD4 and the percentage of samples with a count <25, 25-50, 51-75 and >75-<100 cells/µl were assessed. RESULTS: Specimen data of 11 944 929 CD4 results included 1 306 456 CrAg tests. Annual CD4 and CrAg test volumes declined by 22.4% and 27.8% for 2020 and 2021 respectively (relative to 2018). There were 23 670 CrAg positive outcomes in 2018 compared to 21 399 (-9.6%) and 17 847 (-24.6%) in 2020 and 2021 respectively. A monthly test volume reduction of up to 36.6%, 35.5%, 36.1% and 13.3% was reported for infection waves one to four. CrAg detection increased from 6.3% in 2018 to 7.5% in 2020. More testing was offered to males (>56%) with a higher detection rate of 8.1% in 2020. Between 81.0% and 81.8% of testing was for patients aged 20 to 49 years. The monthly percentage of specimens <25 cells/µl ranged from 30.2% (June 2019) to 35.3% (August 2020). Overall, the monthly median CD4 ranged from 39 (IQR: 15-70)(August 2020) to 45 (IQR: 19-72)(March 2019) cells/µl. In 2020, the provincial percentage change in CrAg test volumes ranged from 2.9% to -33.7%. CONCLUSION: Our findings confirmed the impact of lockdown measures on both the absolute number of CrAg tests performed and detection (increase in 2020). A smaller impact on the median CD4 was noted. The long-term impact on patient management in immune- compromised individuals needs further investigation.
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This manuscript investigates the structural and electrical properties of a Ba0.75Bi0.25Ni0.7Mn0.3O3 (BNMO) perovskite compound synthesized through the sol-gel method. The orthorhombic crystal structure of the sample is confirmed by X-ray diffraction analysis. The electrical conductivity of BNMO is found to increase with frequency, indicating the presence of local charge carriers. The AC electrical conductivity follows Jonscher's equation, exhibiting a plateau at low frequencies and a power-law behavior at high frequencies. The activation energy for conduction is determined to be 0.654 eV. Impedance spectroscopy reveals the presence of grain and grain boundary contributions, which are modeled using an R-CPE combination circuit. Analysis of the electrical modulus demonstrates non-Debye type relaxation and indicates the presence of charge carrier hopping between Mn2+ and Mn3+ ions. The activation energy obtained from the relaxation peaks of the modulus is found to be 0.674 eV. The dielectric constant exhibits high values that increase with temperature. This observation suggests that the capacitance behavior holds promising potential for energy storage applications, making it a suitable candidate for various technological uses.
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The high demand for SARS-CoV-2 tests but limited supply to South African laboratories early in the COVID-19 pandemic resulted in a heterogenous diagnostic footprint of open and closed molecular testing platforms being implemented. Ongoing monitoring of the performance of these multiple and varied systems required novel approaches, especially during the circulation of variants. The National Health Laboratory Service centrally collected cycle threshold (Ct) values from 1,497,669 test results reported from 6 commonly used PCR assays in 36 months, and visually monitored changes in their median Ct within a 28-day centered moving average for each assays' gene targets. This continuous quality monitoring rapidly identified delayed hybridization of RdRp in the Allplex™ SARS-CoV-2 assay due to the Delta (B.1.617.2) variant; S-gene target failure in the TaqPath™ COVID-19 assay due to B.1.1.7 (Alpha) and the B.1.1.529 (Omicron); and recently E-gene delayed hybridization in the Xpert® Xpress SARS-CoV-2 due to XBB.1.5. This near "real-time" monitoring helped inform the need for sequencing and the importance of multiplex molecular nucleic acid amplification technology designs used in diagnostics for patient care. This continuous quality monitoring approach at the granularity of Ct values should be included in ongoing surveillance and with application to other disease use cases that rely on molecular diagnostics.
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Biofilm-related implant infections pose a substantial threat to patients, leading to inflammation in the surrounding tissue, and often resulting in implant loss and the necessity for additional surgeries. Overcoming this implantology challenge is crucial to ensure the success and durability of implants. This study shows the development of antibacterial materials for implant coatings by incorporating copper into 45S5 Bioglass®. By combining the regenerative properties of Bioglass® with the antimicrobial effects of copper, this material has the potential to prevent infections, enhance osseointegration and improve the long-term success of implants. Bioglasses modified with various concentrations of CuO (from 0 to 8 mol%) were prepared with the melt-quenching technique. Structural analysis using Raman and FTIR spectroscopies did not reveal significant alterations in the bioglasses structure with the addition of Cu. The antibacterial activity of the samples was assessed against Gram-positive and Gram-negative bacteria, and the results demonstrated significant inhibition of bacterial growth for the bioglass with 0.5 mol% of CuO. Cell viability studies indicated that the samples modified with up to 4 mol% of CuO maintained good cytocompatibility with the Saos-2 cell line at extract concentrations up to 25 mg/mL. Furthermore, the bioactivity assessment demonstrated the formation of a calcium phosphate (CaP)-rich layer on the surfaces of all bioglasses within 24 h. Our findings show that the inclusion of copper in the bioglass offers a significant enhancement in its potential as a coating material for implants, resulting in notable advancements in both antibacterial efficacy and osteointegration properties.