33 research outputs found

    Improving the biomethane yield from food waste by boosting hydrogenotrophic methanogenesis

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    Anaerobic digestion of food waste is usually impacted by high levels of VFAs, resulting in low pH and inhibited methane production from acetate (acetoclastic methanogenesis); however, this could be harnessed for improving methane production via hydrogenotrophic methanogenesis (biomethanation). In this study, batch anaerobic digestion of food waste was conducted to enhance biomethanation by supplying hydrogen gas (H2), using a gas mixture of 5%-H2 and 95%-N2. The addition of H2 influenced a temporal microbial shift in substrate utilisation from dissolved organic nutrients to H2 and CO2 and was perceived to have enhanced the hydrogenotrophic methanogenic activity. As a result, with the release of hydrogen as degradation progressed (secondary fermentation) hydrogenotrophic methanogenesis was further enriched. This resulted in an enhancement of the upgrading of the biogas, with a 12.1% increase in biomethane (from 417.6 to 468.3 NmL-CH4/gVSadded) and 38.9% reduction in CO2 (from 227.1 to 138.7 NmL-CO2/gVSadded). Furthermore, the availability of hydrogen gas at the start of the process promoted faster propionate degradation, by the enhanced activity of the H2-utilisers, thereby, reducing likely propionate-induced inhibitions. The high level of acidification from VFAs production helped to prevent excessive pH increases from the enhanced hydrogenotrophic methanogenic activity. Therefore, it was found that the addition of hydrogen gas to AD reactors treating food waste showed great potential for enhanced methane yield and biogas upgrade, supported by VFAs-induced pH buffer. This creates the possibility to optimise hydrogenotrophic methanogenesis towards obtaining biogas of the right quality for injection into the gas grid

    Diagnosis of malaria parasitemia in children using a rapid diagnostic test

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    Aim: This cross-sectional study was conducted to evaluate the diagnostic performance of a new rapid immunochromatographic test named “Paracheck pf” in the diagnosis of malaria in Nigerian children.Materials and Methods: A total of 380 Nigerian children aged between 6 and 59 months who presented at the University of Nigeria Teaching Hospital (UNTH) Enugu with fever and no obvious focus of any other infection were consecutively recruited. Malaria parasitemia was determined using simple microscopy and “Paracheck pf”.Results: “Paracheck pf” has the following diagnostic performance characteristics: Sensitivity of 82%, specificity of 91.5%, negative predictive value of 91.5%, positive predictive value of 82%, a strong positive correlation between parasite density and test sensitivity, and a detection limit of 397 parasites/ml.Conclusions: The test is, therefore, recommended for the use in Nigerian children aged between 6 and 59 months in Enugu for the diagnosis of malaria, but negative results should be cautiously interpreted in infants because symptomatic malaria may occur in these children at parasite densities as low as 100/ml

    Pilot Study on Laparoscopic Surgery in Port‑Harcourt, Nigeria

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    Background: Video‑laparoscopic surgery has long been practiced in western countries; however documented practice of this minimal access surgical technique are recently emanating from Nigeria. To the best of our knowledge, this is the first documented study on laparoscopic surgery from the Niger Delta region. Aim: To evaluate the feasibility of laparoscopy as a useful tool for management of common surgical abdominal conditions in our environment. Patients and Methods: This was a prospective outcome study of all consecutive surgical patients who had laparoscopic procedures in general and pediatric surgery units of our institution from August 2011 to December 2012. Data on patient’s age, gender, indication for surgery, duration of hospital stay and outcome of surgery were collected and analyzed. Results: A total of 15 laparoscopic procedures were performed during this study period with age range of 2‑65 years; mean: 32.27 ± 17.86 years. There were 11 males and four females. Six laparoscopic appendicectomies, one laparoscopy‑assisted orchidopexy, five diagnostic laparoscopy ± biopsy, one laparoscopic trans‑abdominal pre‑peritoneal herniorrhaphy for bilateral indirect inguinal hernia and two laparoscopic adhesiolysis for small bowel obstruction were performed. All were successfully completed except one conversion (6.7%) for uncontrollable bleeding in an intra‑abdominal tumor. Conclusion: The practice of laparoscopic surgery in our environment is feasible and safe despite the numerous, but surmountable challenges. There is the need for adequate training of the support staff and a dedicated theatre suite.Keywords: General, laparoscopy, pediatric surger

    In vitro Anticancer Screening of 24 Locally Used Nigerian Medicinal Plants

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    Background: Plants that are used as traditional medicine represent a relevant pool for selecting plant candidates that may have anticancer properties. In this study, the ethnomedicinal approach was used to select several medicinal plants native to Nigeria, on the basis of their local or traditional uses. The collected plants were then evaluated for cytoxicity. Methods: The antitumor activity of methanolic extracts obtained from 24 of the selected plants, were evaluated in vitro on five human cancer cell lines. Results: Results obtained from the plants screened indicate that 18 plant extracts of folk medicine exhibited promising cytotoxic activity against human carcinoma cell lines. Erythrophleum suaveolens (Guill. & Perr.) Brenan was found to demonstrate potent anti-cancer activity in this study exhibiting IC50 = 0.2-1.3 μ\mug/ml. Conclusions: Based on the significantly potent activity of some plants extracts reported here, further studies aimed at mechanism elucidation and bio-guided isolation of active anticancer compounds is currently underway.Chemistry and Chemical Biolog

    Antimicrobial and antioxidant properties of methanol extract, fractions and compounds from the stem bark of Entada abyssinica Stend ex A. Satabie

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    <p>Abstract</p> <p>Background</p> <p>The aim of this study was to evaluate the antimicrobial and antioxidant activities of the methanol extract, fractions and isolated compounds from <it>Entada abyssinica </it>stem bark, plant used traditionally against gastrointestinal infections.</p> <p>Methods</p> <p>The methanol extract of <it>E. abyssinica </it>stem bark was pre-dissolved in a mixture of methanol and water, and then partitioned between <it>n</it>-hexane, ethyl acetate and <it>n</it>-butanol. The ethyl acetate portion was fractionated by column chromatography and the structures of isolated compounds elucidated by analysis of spectroscopic data and comparison with literature data. Antimicrobial activity was assayed by broth microdilution techniques on bacteria and yeasts. The antioxidant activity was determined by DPPH radical scavenging method.</p> <p>Results</p> <p>Four known compounds [(5<it>S</it>,6<it>R</it>,8a<it>R</it>)-5-(carboxymethyl)-3,4,4a,5,6,7,8,8a-octahydro-5,6,8a-trimethylnaphthalenecarboxylic acid (<b>1</b>), methyl 3,4,5-trihydroxybenzoate (<b>2</b>), benzene-1,2,3-triol (<b>3</b>) and 2,3-dihydroxypropyltriacontanoate (<b>4</b>)] were isolated. Compared to the methanol extract, fractionation increased the antibacterial activities of the <it>n</it>-hexane and ethyl acetate fractions, while the antifungal activities increased in ethyl acetate, <it>n</it>-butanol and aqueous residue fractions. The isolated compounds were generally more active on bacteria (9.7 to 156.2 μg/ml) than yeasts (78.1 to 312.5 μg/ml). Apart from compound <b>1</b>, the three others displayed DPPH<sup>· </sup>scavenging activity (RSa), with RSa<sub>50 </sub>values of 1.45 and 1.60 μg/ml.</p> <p>Conclusion</p> <p>The results obtained from this study support the ethnomedicinal use of <it>E. abyssinica </it>in the treatment of gastrointestinal infections and the isolated compounds could be useful in the standardisation of antimicrobial phytomedicine from this plant.</p

    An appraisal of rehabilitation regimes used for improving functional outcome after total hip replacement surgery

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    This study aimed to systematically review the literature with regards to studies of rehabilitation programmes that have tried to improve function after total hip replacement (THR) surgery. 15 randomised controlled trials were identified of which 11 were centre-based, 2 were home based and 2 were trials comparing home and centre based interventions. The use of a progressive resistance training (PRT) programme led to significant improvement in muscle strength and function if the intervention was carried out early (< 1 month following surgery) in a centre (6/11 centre-based studies used PRT), or late (> 1 month following surgery) in a home based setting (2/2 home based studies used PRT). In direct comparison, there was no difference in functional measures between home and centre based programmes (2 studies), with PRT not included in the regimes prescribed. A limitation of the majority of these intervention studies was the short period of follow up. Centre based program delivery is expensive as high costs are associated with supervision, facility provision, and transport of patients. Early interventions are important to counteract the deficit in muscle strength in the affected limb, as well as persistent atrophy that exists around the affected hip at 2 years post-operatively. Studies of early home-based regimes featuring PRT with long term follow up are needed to address the problems currently associated with rehabilitation following THR

    Patient attributes warranting consideration in clinical practice guidelines, health workforce planning and policy

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    <p>Abstract</p> <p>Background</p> <p>In order for clinical practice guidelines (CPGs) to meet their broad objective of enhancing the quality of care and supporting improved patient outcomes, they must address the needs of diverse patient populations. We set out to explore the patient attributes that are likely to demand a unique approach to the management of chronic disease, and which are crucial if evidence or services planning is to reflect clinic populations. These were incorporated into a new conceptual framework; using diabetes mellitus as an exemplar.</p> <p>Methods</p> <p>The patient attributes that informed the framework were identified from CPGs, the diabetes literature, an expert academic panel, and two cross-disciplinary panels; and agreed upon using a modified nominal group technique.</p> <p>Results</p> <p>Full consensus was reached on twenty-four attributes. These factors fell into one of three themes: (1) type/stage of disease, (2) morbid events, and (3) factors impacting on capacity to self-care. These three themes were incorporated in a convenient way in the workforce evidence-based (WEB) model.</p> <p>Conclusions</p> <p>While biomedical factors are frequently recognised in published clinical practice guidelines, little attention is given to attributes influencing a person's capacity to self-care. Paying explicit attention to predictable threats to effective self-care in clinical practice guidelines, by drawing on the WEB model, may assist in refinements that would address observed disparities in health outcomes across socio-economic groups. The WEB model also provides a framework to inform clinical training, and health services and workforce planning and research; including the assessment of healthcare needs, and the allocation of healthcare resources.</p

    The Human Sweet Tooth

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    Humans love the taste of sugar and the word "sweet" is used to describe not only this basic taste quality but also something that is desirable or pleasurable, e.g., la dolce vita. Although sugar or sweetened foods are generally among the most preferred choices, not everyone likes sugar, especially at high concentrations. The focus of my group's research is to understand why some people have a sweet tooth and others do not. We have used genetic and molecular techniques in humans, rats, mice, cats and primates to understand the origins of sweet taste perception. Our studies demonstrate that there are two sweet receptor genes (TAS1R2 and TAS1R3), and alleles of one of the two genes predict the avidity with which some mammals drink sweet solutions. We also find a relationship between sweet and bitter perception. Children who are genetically more sensitive to bitter compounds report that very sweet solutions are more pleasant and they prefer sweet carbonated beverages more than milk, relative to less bitter-sensitive peers. Overall, people differ in their ability to perceive the basic tastes, and particular constellations of genes and experience may drive some people, but not others, toward a caries-inducing sweet diet. Future studies will be designed to understand how a genetic preference for sweet food and drink might contribute to the development of dental caries

    Global, regional, and national incidence, prevalence, and mortality of HIV, 1980–2017, and forecasts to 2030, for 195 countries and territories: a systematic analysis for the Global Burden of Diseases, Injuries, and Risk Factors Study 2017

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    Background Understanding the patterns of HIV/AIDS epidemics is crucial to tracking and monitoring the progress of prevention and control efforts in countries. We provide a comprehensive assessment of the levels and trends of HIV/AIDS incidence, prevalence, mortality, and coverage of antiretroviral therapy (ART) for 1980–2017 and forecast these estimates to 2030 for 195 countries and territories. Methods We determined a modelling strategy for each country on the basis of the availability and quality of data. For countries and territories with data from population-based seroprevalence surveys or antenatal care clinics, we estimated prevalence and incidence using an open-source version of the Estimation and Projection Package—a natural history model originally developed by the UNAIDS Reference Group on Estimates, Modelling, and Projections. For countries with cause-specific vital registration data, we corrected data for garbage coding (ie, deaths coded to an intermediate, immediate, or poorly defined cause) and HIV misclassification. We developed a process of cohort incidence bias adjustment to use information on survival and deaths recorded in vital registration to back-calculate HIV incidence. For countries without any representative data on HIV, we produced incidence estimates by pulling information from observed bias in the geographical region. We used a re-coded version of the Spectrum model (a cohort component model that uses rates of disease progression and HIV mortality on and off ART) to produce age-sex-specific incidence, prevalence, and mortality, and treatment coverage results for all countries, and forecast these measures to 2030 using Spectrum with inputs that were extended on the basis of past trends in treatment scale-up and new infections. Findings Global HIV mortality peaked in 2006 with 1·95 million deaths (95% uncertainty interval 1·87–2·04) and has since decreased to 0·95 million deaths (0·91–1·01) in 2017. New cases of HIV globally peaked in 1999 (3·16 million, 2·79–3·67) and since then have gradually decreased to 1·94 million (1·63–2·29) in 2017. These trends, along with ART scale-up, have globally resulted in increased prevalence, with 36·8 million (34·8–39·2) people living with HIV in 2017. Prevalence of HIV was highest in southern sub-Saharan Africa in 2017, and countries in the region had ART coverage ranging from 65·7% in Lesotho to 85·7% in eSwatini. Our forecasts showed that 54 countries will meet the UNAIDS target of 81% ART coverage by 2020 and 12 countries are on track to meet 90% ART coverage by 2030. Forecasted results estimate that few countries will meet the UNAIDS 2020 and 2030 mortality and incidence targets. Interpretation Despite progress in reducing HIV-related mortality over the past decade, slow decreases in incidence, combined with the current context of stagnated funding for related interventions, mean that many countries are not on track to reach the 2020 and 2030 global targets for reduction in incidence and mortality. With a growing population of people living with HIV, it will continue to be a major threat to public health for years to come. The pace of progress needs to be hastened by continuing to expand access to ART and increasing investments in proven HIV prevention initiatives that can be scaled up to have population-level impact
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