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Earthworms are bioindicators of soil pollution. The ecotoxicity of tailings from selected gold mines in South Africa was investigated utilizing Eisenia andrei bioassays and biomarkers. Samples were obtained from unrehabilitated, rehabilitated and naturally vegetated sites. Biomass, neutral red retention time (NRRT), survival and reproduction were assessed using standardized protocols. Earthworm biomass, NRRT and reproductive success in rehabilitated tailings (comparable to naturally vegetated site) were significantly higher (p < 0.05) than in unrehabilitated tailings. In addition, significantly lower (p < 0.05) body tissue concentrations of As, Cd, Co, Cu and Ni contents were found in the rehabilitated tailings compared to the unrehabilitated. Further, significantly lower (p < 0.05) soil Mn and Zn concentrations were obtained in unrehabilitated tailings than the rehabilitated and naturally vegetated sites. Overall, reduced ecotoxicity effects were confirmed in rehabilitated compared to unrehabilitated tailings. This suggests that rehabilitation as a post-mining restorative strategy has strong positive influence on mine tailings.
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Monitoramento Ambiental , Recuperação e Remediação Ambiental , Mineração , Poluentes do Solo/toxicidade , Animais , Bioensaio , Biomassa , Poluição Ambiental/estatística & dados numéricos , Ouro , Oligoquetos/fisiologia , Solo/química , Poluentes do Solo/análise , África do SulRESUMO
BACKGROUND: South Africa did not meet the MDG targets to reduce TB prevalence and mortality by 50% by 2015, and the TB cure rate remains below the WHO target of 85%. TB incidence in the country is largely fuelled by the HIV epidemic, and co-infected patients are more likely to have unsuccessful TB treatment outcomes. This paper analyses the demographic and clinical characteristics of new TB patients with unsuccessful treatment outcomes, as well as factors associated with unsuccessful treatment outcomes for HIV co-infected patients. METHODS: A cross-sectional retrospective record review of routinely collected data for new TB cases registered in the Free State provincial electronic TB database between 2009 and 2012. The outcome variable, unsuccessful treatment, was defined as cases ≥15 years that 'died', 'failed' or 'defaulted' as the recorded treatment outcome. The data were subjected to descriptive and logistic regression analyses. RESULTS: From 2009 to 2012 there were 66,940 new TB cases among persons ≥15 years (with a recorded TB treatment outcome), of these 61% were co-infected with HIV. Unsuccessful TB treatment outcomes were recorded for 24.5% of co-infected cases and 15.3% of HIV-negative cases. In 2009, co-infected cases were 2.35 times more at risk for an unsuccessful TB treatment outcome (OR: 2.35; CI: 2.06-2.69); this figure decreased to 1.8 times by 2012 (OR: 1.80; CI: 1.63-1.99). Among the co-infected cases, main risk factors for unsuccessful treatment outcomes were: ≥ 65 years (AOR: 1.71; CI: 1.25-2.35); receiving treatment in healthcare facilities in District D (AOR: 1.15; CI 1.05-1.28); and taking CPT (and not ART) (AOR: 1.28; CI: 1.05-1.57). Females (AOR: 0.93; CI: 0.88-0.99) and cases with a CD4 count >350 (AOR: 0.40; CI: 0.36-0.44) were less likely to have an unsuccessful treatment outcome. CONCLUSIONS: The importance of TB-HIV/AIDS treatment integration is evident as co-infected patients on both ART and CPT, and those who have a higher CD4 count are less likely to have an unsuccessful TB treatment outcome. Furthermore, co-infected patients who require more programmatic attention are older people and males.
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Antituberculosos/uso terapêutico , Coinfecção , Infecções por HIV , Falha de Tratamento , Tuberculose Pulmonar/tratamento farmacológico , Adulto , Coinfecção/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Auditoria Médica , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Fatores de Risco , África do Sul/epidemiologia , Resultado do TratamentoRESUMO
Multiplexing of the Linac Coherent Light Source beam was demonstrated for hard X-rays by spectral division using a near-perfect diamond thin-crystal monochromator operating in the Bragg geometry. The wavefront and coherence properties of both the reflected and transmitted beams were well preserved, thus allowing simultaneous measurements at two separate instruments. In this report, the structure determination of a prototypical protein was performed using serial femtosecond crystallography simultaneously with a femtosecond time-resolved XANES studies of photoexcited spin transition dynamics in an iron spin-crossover system. The results of both experiments using the multiplexed beams are similar to those obtained separately, using a dedicated beam, with no significant differences in quality.
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Background: Interstitial lung disease (ILD) is highly prevalent in patients with connective tissue disease (CTD) and is poorly characterised in South Africa. Objectives: To describe the clinical, serological and radiological features of CTD-ILD and their associations in patients attending a tertiary referral hospital. Methods: A cross-sectional study collating clinical, serological and radiological features of CTD-ILD in patients attending rheumatology and respiratory outpatient clinics in a tertiary referral hospital. Results: Of 124 CTD-ILD patients, 37 (29.8%) had rheumatoid arthritis (RA), 32 (25.8%) systemic sclerosis (SSc) and 55 (44.4%) other autoimmune connective tissue diseases (OCTD). Most patients were female (86.3%), of mixed racial ancestry (75.0%), and the median age was 55 years. Nonspecific interstitial pneumonia (NSIP) was the most common ILD pattern (63.7%), followed by usual interstitial pneumonia (UIP) (26.6%). Overall, 60.5% were current or past smokers, 33.1% had previous pulmonary tuberculosis infection, and 75.6% had gastro-oesophageal reflux disease. Patients with RA were older, had similar frequencies of NSIP and UIP, and had significantly better pulmonary function tests than the SSc and OCTD groups. Within three years of CTD diagnosis, two-thirds of the SSc and OCTD patients and almost half of the RA patients had developed ILD. Clinical features, chest X-rays and pulmonary function tests correlated poorly with high-resolution computerised tomography (HRCT). No case of acute pneumonitis was documented in CTD-ILD patients treated with methotrexate (MTX). Conclusion: We suggest routine HRCT in all newly diagnosed CTD patients, particularly those with SSc and OCTD, where more than two-thirds of the patients had developed ILD within three years of their CTD. The use of MTX was not associated with the development of acute pneumonitis in patients with ILD. Key points: Clinical features, chest X-rays and pulmonary function tests correlated poorly with high-resolution computerised tomography (HRCT).Smoking, environmental toxins, gastro-oesophogeal reflux and previous pulmonary tuberculosis infection were significant comorbidities in CTD-ILD patients.Early screening of ILD with HRCT is recommended, particularly in SSc.Use of MTX before and after ILD diagnosis was not associated with acute pneumonitis.
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Green synthesis of metal nanoparticles is reputed to have a robust range of biomedical applications. Silver nanoparticles (AgNPs) bio-fabricated using aqueous leaf extract of Annona muricata were characterized and evaluated for in-vitro antioxidant, lipid peroxidation inhibition, anti-diabetic and antimicrobial activities as well as cytotoxicity in human keratinocyte cells (HaCaT). The extract induced colour change of silver salt solution which absorbed at 420 nm and confirmed the formation of AgNPs. FTIR showed that free amide and hydroxyl groups were responsible for the synthesized nanoparticles. Both XRD and SAED confirmed the crystalline nature of the particles with face centered cubic (FCC) phase. The zeta potential revealed -27.2 mV potential and average distribution size of 35 nm. DLS indicated that the majority of the particles were 86.78 nm size and with a polydispersity index (PDI) of 0.329. AgNPs displayed strong activities against DPPH (IC50 = 51.80 µg/ml), ABTS (IC50 = 30.78 µg/ml), α-amylase (IC50 = 0.90 µg/ml) and α-glucosidase (IC50 = 3.32 µg/ml). The particles exhibited a dose-dependent inhibition of Fe2+-induced lipid peroxidation with effective antimicrobial activity against a battery of bacterial strains and cytotoxicity in HaCaT cell line. These findings revealed the potential biomedical applications of the particles and further work will be required to establish its molecular mechanism of action.
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Carcinoma de Células Escamosas/genética , Doenças em Gêmeos , Neoplasias Faciais/genética , Neoplasias Bucais/genética , Neoplasias Cutâneas/genética , Xeroderma Pigmentoso/genética , Queilite/genética , Criança , Diagnóstico Diferencial , Humanos , Neoplasias Labiais/genética , Masculino , Úlceras Orais/genética , Neoplasias da Língua/genéticaRESUMO
Human pathogenic diseases are on the rampage in the list of debilitating diseases globally. The endless quest to salvage this menace through various therapies via innocuous agents is essential to overcome these drug-resistant pathogens. This study engaged a benign, facile, biocompatible, cost-effective and eco-friendly approach to synthesized iron oxide nanoparticles (FeO-NPs) via a composite of Psidium guavaja-Moringa oleifera (PMC) leaf extract to address six most debilitating bacterial strain in vitro as an antibacterial agent. Physicochemical analysis of PMC formed nanoparticles (PMC_NPs) was effectuated through Fourier Transform Infrared Spectroscopy (FT-IR), UV-Visible Spectroscopy, X-ray Diffraction Spectroscopy (XRD), Transmission Electron Microscopy (TEM), and Vibrating Sample Magnetometer (VSM). The PMC_NPs inhibited the growth of six human pathogens with higher activity at lower concentrations. It is noteworthy from our observations that, the bacterial strains show functional susceptibility to the PMC_NPs at lower concentrations compared to the orthodox antibacterial drugs. Photocatalytic degradation was observed with a decrease in the absorbance of Methylene blue dyes with the help of PMC_NPs apropos irradiation time under visible light irradiation. Consequently, PMC_NPs serve as an enhanced substitute for the orthodox antibacterial drugs in therapeutic biomedical field sequel to its pharmacodynamics against the bacterial strains at lower concentrations and also serves as a good component for water purification.
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Antibacterianos/química , Nanopartículas de Magnetita/química , Moringa oleifera/química , Extratos Vegetais/química , Psidium/química , Bactérias/efeitos dos fármacos , Vias Biossintéticas , Catálise , Química Verde/métodos , Humanos , Azul de Metileno/química , Tamanho da Partícula , Processos Fotoquímicos , Propriedades de SuperfícieRESUMO
During the past few years, serial crystallography methods have undergone continuous development and serial data collection has become well established at high-intensity synchrotron-radiation beamlines and XFEL radiation sources. However, the application of experimental phasing to serial crystallography data has remained a challenging task owing to the inherent inaccuracy of the diffraction data. Here, a particularly gentle method for incorporating heavy atoms into micrometre-sized crystals utilizing lipidic cubic phase (LCP) as a carrier medium is reported. Soaking in LCP prior to data collection offers a new, efficient and gentle approach for preparing heavy-atom-derivative crystals directly before diffraction data collection using serial crystallography methods. This approach supports effective phasing by utilizing a reasonably low number of diffraction patterns. Using synchrotron radiation and exploiting the anomalous scattering signal of mercury for single isomorphous replacement with anomalous scattering (SIRAS) phasing resulted in high-quality electron-density maps that were sufficient for building a complete structural model of proteinase K at 1.9â Å resolution using automatic model-building tools.
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There is a risk of shortening and toughening with hot-deboning of muscles. However, with refrigerated aging this phenomenon may be negated. Vacuum-packed hot and cold-deboned ostrich Muscularis gastrocnemius, pars interna were stored for 21 d at 4°C to investigate the effects of hot-deboning on quality characteristics of ostrich meat during refrigerated storage. Muscle pH did not differ (P>0.05) between hot and cold-deboned muscles during storage. Hot-deboning caused (P<0.0001) more purge in the vacuum packages of the hot-deboned muscles (1.83±1.31%) than in the cold-deboned muscles (0.67±075%) during the 21-d aging period. Hot-deboned muscles were tougher (P<0.05) than cold-deboned muscles from 24h up to 5 d. Although hot-deboning caused muscles to be tougher than cold-deboned muscles, with aging at 4°C beyond 5 d this toughness was found to be insignificant.
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OBJECTIVE: The objective of this retrospective analysis was to study the etiology, distribution, treatment modalities and complications of mandibular fractures of patients who attended the Maxillo-Facial and Oral Surgery (MFOS) unit at the School of Dentistry, University of Pretoria. METHOD: The records of a representative sample of patients who presented at the MFOS unit with mandibular fractures between January 1999 and December 2003 were captured on a data form specifically designed for this purpose. The data were then analysed using the Statistix 8 programme. RESULTS: Of the 501 patients who were included in the survey, 67.6% were in the age group 21 to 40 years. The majority of the patients (83.2%) were male. Assault (72.5%) was the most common cause of injury followed by road traffic accidents (14.2 %) and falls (8.8%). Of the 501 cases, 41.3% were bilateral, 32.7% on the left side and 26% on the right side. With regard to the location of the fractures, the majority occurred in the body of the mandible (411%), followed by those in the area of the symphysis/ parasymphysis (23.1%). In the majority of cases (51.7%) the treatment modality used was a closed reduction with intermaxillary fixation. Complications were reported in 14.6% of the 501 cases of which malunion (32%) was the most prevalent. CONCLUSIONS: Mandibular fractures are more common in males in the age range 21 to 40 years. Interpersonal violence is the main cause of these fractures. The majority of mandibular fractures occur in the body region while malunion is the most common complication.
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Acidentes de Trânsito , Fraturas Mandibulares/epidemiologia , Violência/estatística & dados numéricos , Adolescente , Adulto , Distribuição por Idade , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Fraturas Mandibulares/etiologia , Fraturas Mandibulares/terapia , Pessoa de Meia-Idade , Estudos Retrospectivos , Distribuição por Sexo , África do Sul/epidemiologiaRESUMO
OBJECTIVE: To determine and describe the factors influencing treatment default of tuberculosis (TB) patients in the Free State Province of South Africa. METHODS: A retrospective records review of pulmonary TB cases captured in the ETR.Net electronic TB register between 2003 and 2012 was performed. Subjects were >15 years of age and had a recorded pre-treatment smear result. The demographic and clinical characteristics of defaulters were described. Multivariate logistic regression analysis was used to determine factors associated with treatment default. The odds ratios (OR) together with their corresponding 95% confidence intervals (CI) were estimated. Statistical significance was considered at 0.05. RESULTS: A total of 7980 out of 110 349 (7.2%) cases defaulted treatment. Significantly higher proportions of cases were male (8.3% vs. female: 5.8%; p<0.001), <25 years old (9.1% vs. 25-34 years: 8.7%; 35-44 years: 7.0%; 45-54 years: 5.2%; 55-64 years: 4.4%; >64 years: 3.9%; p<0.001), undergoing TB retreatment (11.0% vs. new cases: 6.3%; p<0.001), had a negative pre-treatment sputum smear result (7.8% vs. positive smear results: 7.1%; p<0.001), were in the first 2 months of treatment (95.5% vs. >2 months: 4.8%; p<0.001), and had unknown HIV status (7.8% vs. HIV-positive: 7.0% and HIV-negative: 5.7%; p<0.001). After controlling for potential confounders, multivariate analysis revealed a two-fold increased risk of defaulting treatment when being retreated compared to being treated for the first time for TB (adjusted OR (AOR) 2.0, 95% CI 1.85-2.25). Female cases were 40% less likely to default treatment compared to their male counterparts (AOR 0.6, 95% CI 0.51-0.71). Treatment default was less likely among cases >24 years old compared to younger cases (25-34 years: AOR 0.8, 95% CI 0.77-0.87; 35-44 years: AOR 0.6, 95% CI 0.50-0.64; 45-54 years: AOR 0.4, 95% CI 0.32-0.49; 55-64 years: AOR 0.3, 95% CI 0.21-0.43; >64 years: AOR 0.3, 95% CI 0.19-0.35). Co-infected cases receiving antiretroviral therapy (ART) were 40% less likely to default TB treatment relative to those whose ART status was unknown (AOR 0.6, 95% CI 0.46-0.57). CONCLUSIONS: Salient factors influence TB patient treatment default in the Free State Province. Therefore, the strengthening of clinical and programmatic interventions for patients at high risk of treatment default is recommended. In particular, ART provision to co-infected cases facilitates TB treatment adherence and outcomes.
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Antituberculosos/uso terapêutico , Tuberculose/tratamento farmacológico , Adolescente , Adulto , Idoso , Fármacos Anti-HIV/uso terapêutico , Coinfecção/tratamento farmacológico , Coinfecção/epidemiologia , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estudos Retrospectivos , Fatores de Risco , África do Sul/epidemiologia , Resultado do Tratamento , Tuberculose/epidemiologia , Adulto JovemRESUMO
Consistent reports indicate that hypertension is a particularly common finding in black populations. Hypertension occurs at younger ages and is often more severe in terms of blood pressure levels and organ damage than in whites, resulting in a higher incidence of cardiovascular disease and mortality. This review provides an outline of recent advances in the pathophysiological understanding of blood pressure elevation and the consequences thereof in black populations in Africa. This is set against the backdrop of populations undergoing demanding and rapid demographic transition, where infection with the human immunodeficiency virus predominates, and where under and over-nutrition coexist. Collectively, recent findings from Africa illustrate an increased lifetime risk to hypertension from foetal life onwards. From young ages black populations display early endothelial dysfunction, increased vascular tone and reactivity, microvascular structural adaptions as well as increased aortic stiffness resulting in elevated central and brachial blood pressures during the day and night, when compared to whites. Together with knowledge on the contributions of sympathetic activation and abnormal renal sodium handling, these pathophysiological adaptations result in subclinical and clinical organ damage at younger ages. This overall enhanced understanding on the determinants of blood pressure elevation in blacks encourages (a) novel approaches to assess and manage hypertension in Africa better, (b) further scientific discovery to develop more effective prevention and treatment strategies and
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População Negra , Pressão Sanguínea , Hipertensão/etnologia , África Subsaariana/epidemiologia , Idade de Início , Anti-Hipertensivos/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Comorbidade , Comportamentos Relacionados com a Saúde/etnologia , Humanos , Hipertensão/diagnóstico , Hipertensão/tratamento farmacológico , Hipertensão/fisiopatologia , Estilo de Vida/etnologia , Prognóstico , Fatores de Risco , Índice de Gravidade de DoençaRESUMO
Impression materials used in the analysis of bite marks are required to maintain their stability and integrity for extended periods. It has been observed that certain impressions taken of skin lose their properties with time, becoming sticky and unusable as evidence. The objective of this study was to investigate the onset of "stickiness" in two commonly used dental impression materials when brought into contact with skin. The two materials tested were Impregum and President. They were syringed into glass rings positioned on the upper arms of 28 volunteers. Changes in stickiness were monitored over a four-month period using a tensile testing machine. A metal plunger was lowered onto the impression material and then retracted measuring the adhesive force of the material to the lower surface of the plunger. Over the research period 17 of the 28 rings of Impregum became sticky and changed colour from purple to turquoise. The remaining 11 Impregum samples, all the President samples and all control samples remained unchanged over the 120 day period. The results of this study show that certain factors present in or on skin are responsible for the loss of surface integrity of Impregum. The factors responsible for these changes have not been established.
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Materiais para Moldagem Odontológica/química , Pele/anatomia & histologia , Adesividade , Adulto , Cor , Feminino , Humanos , Masculino , Projetos Piloto , Resinas Sintéticas/química , Silicones/química , Estresse Mecânico , Propriedades de Superfície , Resistência à Tração , Fatores de TempoRESUMO
Doses for standing sedation allowing for various procedures in otherwise inaccessible, untrained captive African elephant bulls are presented. Thirty-three standing sedations were performed in 12 males aged 8-30 years (one to four sedations per animal). Each bull received a combination of 0.009 ± 0.002 mg/kg medetomidine and 0.03 ± 0.007 mg/kg butorphanol. Full sedation was reached on average 25.5 min after injection. The addition of hyaluronidase (1000-2000 IU) significantly reduced time to full sedation to 16.5 min (paired t test, P = 0.024). Reversal was induced with intramuscular atipamezole 0.008 (±0.002) and naltrexone 0.035 (±0.015) mg/kg. Recovery took on average 7 min (3-18 min). The medetomidine/butorphanol combination provided safe standing sedation for smaller procedures.
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Butorfanol/administração & dosagem , Sedação Consciente/veterinária , Elefantes , Medetomidina/administração & dosagem , Fatores Etários , Animais , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Hipnóticos e Sedativos/administração & dosagem , Masculino , PosturaRESUMO
OBJECTIVE: The objective of this study was to make use of a quantitative and qualitative approach comparing the systemic renin-angiotensin system (RAS) of hypertensive black and white African men by using RAS equilibrium analysis. MATERIALS AND METHODS: This sub-study involved 23 black (n = 15) and white (n = 8) hypertensive men aged 39.5-41 years, living in the North West Province of South Africa. The RAS-Fingerprinting was determined with LC-MS/MS quantification of angiotensin peptides. Blood pressure and other variables were determined with known methods. RESULTS: The main finding of this study was the significant lower Ang I (<5.0 and 45.1 pg/ml; p = 0.005) and Ang II (15.6 and 123.9 pg/ml; p ⩽ 0.001) encountered in the hypertensive black African men compared to their white counterparts. Levels of Ang 1-5 (downstream metabolite of Ang 1-7) (1.8 and 3.0 pg/ml), were detected in black and white hypertensive men, respectively. CONCLUSIONS: The observed differences between circulating RAS components, which are reflected via equilibrium angiotensin levels, point to a distinctive molecular regulation of the RAAS in the two study cohorts. The increased peripheral resistance observed in hypertensive black individuals might take over a dominant role in control of blood pressure in this study population. A novel highly sensitive LC-MS/MS method resolved the issue of peptide recovery variations during sample preparation by using internal standards for each individual angiotensin metabolite.
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População Negra , Hipertensão/sangue , Peptídeos/sangue , Sistema Renina-Angiotensina , População Branca , Adulto , Angiotensina II/sangue , Humanos , Masculino , Estatísticas não ParamétricasRESUMO
The purpose of this in vitro investigation was to evaluate the shear bond strength of composite resin bonded to Cerec Vitablocs Mark II porcelain with four different porcelain repair systems. The systems evaluated in this study were Scotchbond/ RelyX Primer (S/ 3M), Ultradent Porcelain Repair Kit (U, Ultradent), Vivadent Ceramic Repair Kit (V, Vivadent) and Prime & Bond NT/ Calibra Silane Coupling Agent (P, Dentsply). Seventy five Cerec Vitablocks Mark II porcelain were embedded in metal rings, leaving 7 mm of porcelain exposed above the ring surface. Samples were ground wet on 400 grit SiC paper to roughen the surface and then screened for surface defects. The five porcelain repair agents were applied according to manufacturers' instructions and matching composite stubbs, then bonded onto 15 treated porcelain surfaces, using an Ultradent mould with a diameter of 2,38 mm. All samples were stored in distilled water for 24 hours at 37 degrees C before the bonds were stressed to failure, using a shear load in a Texture Analyser (TAXT2i) (Stable Micro Systems) Data was analyzed statistically (ANOVA). The effects of the pretreatments on the porcelain surfaces after treatment with the different systems were examined in a Scanning Electron Microscope (SEM), and the modes of fracture were assessed under a light microscope. The mean SBS (MPa) for the products in descending order were: U = 26.6 1.7; V = 20.9 3.4; C = 19.4 5.3; S = 18.0 2.0 and P = 15.9 2.1. The Student-t Test revealed a statistical significant difference (p < 0.05) between the mean shear bond strengths of P and U. There was also a statistical significant difference (p < 0.05) between the mean shear bond strengths of P and V. Most debonded specimens showed cohesive fractures in the porcelain. Significant shear bond strength differences were observed for the different repair systems. All the systems tested can probably be used to repair Cerec Vitablocs Mark II porcelain, with some systems providing higher bond strengths.
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Cerâmica/química , Resinas Compostas/química , Colagem Dentária , Porcelana Dentária/química , Reparação em Prótese Dentária , Resinas Acrílicas/química , Bis-Fenol A-Glicidil Metacrilato/química , Análise do Estresse Dentário , Humanos , Ácido Fluorídrico/química , Teste de Materiais , Microscopia Eletrônica de Varredura , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Poliuretanos/química , Cimentos de Resina/química , Resistência ao Cisalhamento , Silanos/química , Propriedades de SuperfícieRESUMO
BACKGROUND: Selection of medical students at South African (SA) medical schools must promote equitable and fair access to students from all population groups, while ensuring optimal student throughput and success, and training future healthcare practitioners who will fulfil the needs of the local society. In keeping with international practices, a variety of academic and non-academic measures are used to select applicants for medical training programmes in SA medical schools. OBJECTIVES: To provide an overview of the selection procedures used by all eight medical schools in SA, and the student demographics (race and gender) at these medical schools, and to determine to what extent collective practices are achieving the goals of student diversity and inclusivity. METHODS: A retrospective, quantitative, descriptive study design was used. All eight medical schools in SA provided information regarding selection criteria, selection procedures, and student demographics (race and gender). Descriptive analysis of data was done by calculating frequencies and percentages of the variables measured. RESULTS: Medical schools in SA make use of academic and non-academic criteria in their selection processes. The latter include indices of socioeconomic disadvantage. Most undergraduate medical students in SA are black (38.7%), followed by white (33.0%), coloured (13.4%) and Indian/Asian (13.6%). The majority of students are female (62.2%). The number of black students is still proportionately lower than in the general population, while other groups are overrepresented. CONCLUSION: Selection policies for undergraduate medical programmes aimed at redress should be continued and further refined, along with the provision of support to ensure student success.
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Growth of vegetative cells and germination of endospores of Sporolactobacillus at reduced water activity (aw) values were studied with NaCl and glycerol as humectants, and compared with Bacillus cereus and Clostridium sporogenes. With NaCl the highest aw for complete inhibition of both growth of vegetative cells and germinated spores of Sporolactobacillus was 0.955. With glycerol, growth of vegetative cells was completely inhibited at 0.905 as compared to 0.880 for vegetative growth resulting from germinated endospores. The mechanism of this phenomenon cannot be explained yet. NaCl appeared to have a toxic effect, in addition to inhibition by reduced aw per se.
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Lactobacillus/crescimento & desenvolvimento , Água/farmacologia , Bacillus cereus/efeitos dos fármacos , Bacillus cereus/crescimento & desenvolvimento , Bacillus cereus/metabolismo , Clostridium/efeitos dos fármacos , Clostridium/crescimento & desenvolvimento , Clostridium/metabolismo , Glicerol/farmacologia , Lactobacillus/efeitos dos fármacos , Lactobacillus/metabolismo , Cloreto de Sódio/farmacologia , Esporos Bacterianos/efeitos dos fármacos , Esporos Bacterianos/metabolismoRESUMO
In an ecological study only low numbers of Sporolactobacillus were found in habitats such as the faeces of herbivores, the rumen of cattle and the final waste water of an abattoir. Their presence in the final waste water of an abattoir indicates their possible association with food, and, more specifically, with meat. Differences were found in some physiological characteristics. One isolate (L2404) differed from the authentic Sporolactobacillus ATCC 15538 by its inability to ferment inulin, its growth in presence of 6.5% NaCl and in 0.2% tellurite, by the isomer(s) of lactic acid produced and the mol% G + G in the DNA. One Sporolactobacillus isolate (L2407) showed antagonism against Bacillus cereus, Bacillus cereus var, mycoides, Bacillus megaterium and Bacillus subtilis.
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Bacillaceae/fisiologia , Bacillus/fisiologia , Ecologia , Fezes/microbiologia , Animais , Bacillaceae/isolamento & purificação , Bovinos , Microbiologia de Alimentos , Cavalos , Esgotos , Ovinos , Microbiologia da ÁguaRESUMO
Vegetative cells of Sporolactobacillus showed average resistance to gamma-irradiation compared to other vegetative bacteria with D10 values ranging from 0.350 to 0.525 kGy. Endospores of Sporolactobacillus showed higher resistance to gamma-irradiation than most Bacillus species but were close to that of Clostridium species. The average D10 value for Sporolactobacillus endospores was 2.5 kGy.