8,176 research outputs found

    Co-production of bio-oil and propylene through the hydrothermal liquefaction of polyhydroxybutyrate producing cyanobacteria

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    A polyhydroxybutyrate (PHB) producing cyanobacteria was converted through hydrothermal liquefaction (HTL) into propylene and a bio-oil suitable for advanced biofuel production. HTL of model compounds demonstrated that in contrast to proteins and carbohydrates, no synergistic effects were detected when converting PHB in the presence of algae. Subsequently, Synechocystis cf. salina, which had accumulated 7.5wt% PHB was converted via HTL (15% dry weight loading, 340°C). The reaction gave an overall propylene yield of 2.6%, higher than that obtained from the model compounds, in addition to a bio-oil with a low nitrogen content of 4.6%. No propylene was recovered from the alternative non-PHB producing cyanobacterial strains screened, suggesting that PHB is the source of propylene. PHB producing microorganisms could therefore be used as a feedstock for a biorefinery to produce polypropylene and advanced biofuels, with the level of propylene being proportional to the accumulated amount of PHB

    The ART Advantage: Health Care Utilization for Diabetes and Hypertension in Rural South Africa

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    The prevalence of diabetes and hypertension has increased in HIV-positive populations, but there is limited understanding of the role that antiretroviral therapy (ART) programs play in the delivery of services for these conditions. The aim of this study is to assess the relationship between ART use and utilization of health care services for diabetes and hypertension.Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa is a cohort of 5059 adults. The baseline study collects biomarker-based data on HIV, ART, diabetes, and hypertension and self-reported data on health care utilization. We calculated differences in care utilization for diabetes and hypertension by HIV and ART status and used multivariable logistic regressions to estimate the relationship between ART use and utilization of services for these conditions, controlling for age, sex, body mass index, education, and household wealth quintile.Mean age, body mass index, hypertension, and diabetes prevalence were lower in the HIV-positive population (all P < 0.001). Multivariable logistic regression showed that ART use was significantly associated with greater odds of blood pressure measurement [adjusted odds ratio (aOR) 1.27, 95% confidence interval (CI): 1.04 to 1.55] and blood sugar measurement (aOR 1.26, 95% CI: 1.05 to 1.51), counseling regarding exercise (aOR 1.57, 95% CI: 1.11 to 2.22), awareness of hypertension diagnosis (aOR 1.52, 95% CI: 1.12 to 2.05), and treatment for hypertension (aOR 1.63, 95% CI: 1.21 to 2.19).HIV-positive patients who use ART are more likely to have received health care services for diabetes and hypertension. This apparent ART advantage suggests that ART programs may be a vehicle for strengthening health systems for chronic care

    Identifying the optimal donor for natural killer cell adoptive therapy to treat paediatric B- and T-cell acute lymphoblastic leukaemia.

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    Objectives: Natural killer (NK) cells are an attractive source of cells for an 'off the shelf' cellular therapy because of their innate capacity to target malignant cells, and ability to be transferred between donors and patients. However, since not all NK cells are equally effective at targeting cancer, selecting the right donor for cellular therapy is critical for the success of the treatment. Recently, cellular therapies utilising NK cells from cytomegalovirus (CMV)-seropositive donors have been explored. However, whether these NK cells are the best source to treat paediatric acute lymphoblastic leukaemia (ALL) remains unclear. Methods: Using a panel of patient-derived paediatric B- and T-ALL, we assessed the ability of NK cells from 49 healthy donors to mount an effective functional response against these two major subtypes of ALL. Results: From this cohort, we have identified a pool of donors with superior activity against multiple ALL cells. While these donors were more likely to be CMV+, we identified multiple CMVneg donors within this group. Furthermore, NK cells from these donors recognised B- and T-ALL through different activating receptors. Dividing functional NK cells into 29 unique subsets, we observed that within each individual the same NK cell subsets dominated across all ALL cells. Intriguingly, this occurred despite the ALL cells in our panel expressing different combinations of NK cell ligands. Finally, we can demonstrate that cellular therapy products derived from these superior donors significantly delayed leukaemia progression in preclinical models of ALL. Conclusions: We have identified a pool of superior donors that are effective against a range of ALL cells, representing a potential pool of donors that can be used as an adoptive NK cell therapy to treat paediatric ALL

    Synthetic RNA Silencing of Actinorhodin Biosynthesis in Streptomyces coelicolor A3(2)

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    We demonstrate the first application of synthetic RNA gene silencers in Streptomyces coelicolor A3(2). Peptide nucleic acid and expressed antisense RNA silencers successfully inhibited actinorhodin production. Synthetic RNA silencing was target-specific and is a new tool for gene regulation and metabolic engineering studies in Streptomyces.Peer reviewe

    Magnetic resonance lung function – a breakthrough for lung imaging and functional assessment? A phantom study and clinical trial

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    BACKGROUND: Chronic lung diseases are a major issue in public health. A serial pulmonary assessment using imaging techniques free of ionizing radiation and which provides early information on local function impairment would therefore be a considerably important development. Magnetic resonance imaging (MRI) is a powerful tool for the static and dynamic imaging of many organs. Its application in lung imaging however, has been limited due to the low water content of the lung and the artefacts evident at air-tissue interfaces. Many attempts have been made to visualize local ventilation using the inhalation of hyperpolarized gases or gadolinium aerosol responding to MRI. None of these methods are applicable for broad clinical use as they require specific equipment. METHODS: We have shown previously that low-field MRI can be used for static imaging of the lung. Here we show that mathematical processing of data derived from serial MRI scans during the respiratory cycle produces good quality images of local ventilation without any contrast agent. A phantom study and investigations in 85 patients were performed. RESULTS: The phantom study proved our theoretical considerations. In 99 patient investigations good correlation (r = 0.8; p ≤ 0.001) was seen for pulmonary function tests and MR ventilation measurements. Small ventilation defects were visualized. CONCLUSION: With this method, ventilation defects can be diagnosed long before any imaging or pulmonary function test will indicate disease. This surprisingly simple approach could easily be incorporated in clinical routine and may be a breakthrough for lung imaging and functional assessment
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