288 research outputs found

    Isolation of white wine volatiles using different sample preparation methods

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    Three sample preparation methods for gas chromatographic analysis of white wine volatiles were tested. In order to find an adequate replacement for common liquidliquid extraction using 1,1,1-trichlorofluoromethan, headspace solid-phase microextraction (HS-SPME) and stir bar sorptive extraction (SBSE) were tested. SPME and SBSE sample preparations are characterized by rapid and easy handling, small sample size and the possibility of automation, but the recovery of aroma compounds is restricted because of the discrimination properties of the polymer phase. Unlike SPME, the results obtained by SBSE are more similar to those of liquid-liquid extraction.

    Sustainable revenue management

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    The introduction of public transport smart cards means it is now possible to forecast how behavioural change stimulators, such as time-variable pricing, will impact passenger activity. This is an invaluable tool for managing revenue in a sustainable way, not just in the public transport sector, but also for every industry constrained by peak-loading capacity

    Study of phenolic and volatile composition of white wine during fermentation and a short time of storage

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    The phenolic composition including hydroxybenzoic acids, hydroxycinnamic acids and flavan-3-ols was identified and quantified in all studied samples by using a reversed-phase high-performance liquid chromatography (HPLC) system coupled with diode array detection. Gallic, protocatechuic, p-coumaric and vanillic acids were the major phenolic substances in grape juice, whereas caffeic acid was the most abundant phenolic acid in the wine after a short time of storage. For more reliable results, the antioxidant activity of grape juice and wine was measured by β-carotene bleaching (BCB) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging methods.The content changes of volatile compounds in the grape juice and wine were determined by using headspace solid phase microextraction (HS-SPME) coupled with gas chromatography (GC/FID and GC/MS). Hexanal, (E)-2-hexenal, 2-ethyl-1-hexanol, 1-hexanol, (Z)-neroloxide and linalool were the most representative compounds determined in grape juice, whereas ethyl esters of hexanoic, octanoic, decanoic and dodecanoic acids, hexyl acetate, isoamyl acetate, as well as isobutanol, isoamyl alcohol and 1-hexanol were identified as the main compounds.

    The implications of ambitious decarbonisation of heat and road transport for Britain’s net zero carbon energy systems

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    Decarbonisation of heating and road transport are regarded as necessary but very challenging steps on the pathway to net zero carbon emissions. Assessing the most efficient routes to decarbonise these sectors requires an integrated view of energy and road transport systems. Here we describe how a national gas and electricity transmission network model was extended to represent multiple local energy systems and coupled with a national energy demand and road transport model. The integrated models were applied to assess a range of technologies and policies for heating and transport where the UK’s 2050 net zero carbon emissions target is met. Overall, annual primary energy use is projected to reduce by between 25% and 50% by 2050 compared to 2015, due to ambitious efficiency improvements within homes and vehicles. However, both annual and peak electricity demands in 2050 are more than double compared with 2015. Managed electric vehicle charging could save 14TWh/year in gas-fired power generation at peak times, and associated emissions, whilst vehicle-to-grid services could provide 10GW of electricity supply during peak hours. Together, managed vehicle charging, and vehicle-to-grid supplies could result in a 16% reduction in total annual energy costs. The provision of fast public charging facilities could reduce peak electricity demand by 17GW and save an estimated £650 million annually. Although using hydrogen for heating and transport spreads the hydrogen network costs between homeowners and motorists, it is still estimated to be more costly overall compared to an all-electric scenario. Bio-energy electricity generation plants with carbon capture and storage are required to drive overall energy system emissions to net zero, utilisation of which is lowest when heating is electrified, and road transport consists of a mix of electric and hydrogen fuel-cell vehicles. The analysis demonstrates the need for an integrated systems approach to energy and transport policies and for coordination between national and local governments

    Information needs of black prostate cancer patients receiving treatment within the South African public healthcare system

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    INTRODUCTION. Prostate cancer is the leading cancer type in black South African men. The South African public healthcare sector serves more than 84% of the population, which includes many of these men. Previous evidence suggests that patients’ information needs are influenced by culture. No studies could be found that explored the information needs of black men diagnosed with prostate cancer in a developing country from the patients’ perspectives. Therefore, this study set out to investigate the information needs of black men diagnosed with prostate cancer in a South African public healthcare setting. METHODS. Nine participants who had completed a radical course of external beam radiation therapy for prostate cancer were interviewed. These participants had gained experience from their cancer journey in this setting and could therefore provide information-rich perspectives about their information needs from the time of diagnosis to end of treatment. Interviews were conducted in the participants’ preferred language, with three interviews conducted in Zulu with an English translator. RESULTS. Important themes that emerged included patients' desire to receive more information regarding what was happening in the diagnosis stage, the implications of having prostate cancer and the origin of their symptoms. The participants expressed a need to understand the potential side effects of radiation therapy, the reason for bladder filling and on-treatment set-up imaging verification. Participants also wanted to know how they should care for themselves and adjust their lifestyles, and required more information about follow-up tests and appointments. CONCLUSION. In South Africa, black men with prostate cancer expressed the need for more information about the implications of a prostate cancer diagnosis, the reasons for these treatments and what they were expected to do. They also require information about where to go and what will happen in the different parts of the healthcare system with regard to the diagnosis and treatment of the prostate cancer. Communities should also be educated about cancer to avoid misconceptions. In South Africa, healthcare workers should consider the life-worlds of black men in the public healthcare system when attending to their information needs.https://www.springer.com/journal/40487hj2021Radiograph

    Correlative High-Resolution Imaging of Iron Uptake in Lung Macrophages

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    Detection of iron at the subcellular level in order to gain insights into its transport, storage, and therapeutic prospects to prevent cytotoxic effects of excessive iron accumulation is still a challenge. Nanoscale magnetic sector secondary ion mass spectrometry (SIMS) is an excellent candidate for subcellular mapping of elements in cells since it provides high secondary ion collection efficiency and transmission, coupled with high-lateral-resolution capabilities enabled by nanoscale primary ion beams. In this study, we developed correlative methodologies that implement SIMS high-resolution imaging technologies to study accumulation and determine subcellular localization of iron in alveolar macrophages. We employed transmission electron microscopy (TEM) and backscattered electron (BSE) microscopy to obtain structural information and high-resolution analytical tools, NanoSIMS and helium ion microscopy-SIMS (HIM-SIMS) to trace the chemical signature of iron. Chemical information from NanoSIMS was correlated with TEM data, while high-spatial-resolution ion maps from HIM-SIMS analysis were correlated with BSE structural information of the cell. NanoSIMS revealed that iron is accumulating within mitochondria, and both NanoSIMS and HIM-SIMS showed accumulation of iron in electrolucent compartments such as vacuoles, lysosomes, and lipid droplets. This study provides insights into iron metabolism at the subcellular level and has future potential in finding therapeutics to reduce the cytotoxic effects of excessive iron loading

    Effectiveness of some crown compounds on inhibition of polyphenoloxidase in model systems and in apple

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    Enzymatic browning is (in most cases) an undesirable reaction which usually impairs the sensory properties and chemical changes in raw fruits and vegetables after mechanical operations (such as peeling, coring or slicing). A great emphasis is put on research to develop new methods to prevent enzymatic browning especially in fresh-cut (minimally processed) fruits and vegetables. The inhibition effect of crown compounds, macrocyclic ethers, benzo-18-crown-6 with sorbic acid and benzo-18-crown-6 with potassium sorbate, on polyphenoloxidase (PPO) activity was studied. The effectiveness of these compounds was evaluated by using 3,4-dihydroxy phenylalanine (L-DOPA), and chlorogenic acid (3-o-caffeoyl-D-quinic acid), the most widespread natural PPO substrates in fruits and vegetables, as well as browning inhibition substances on the cut surface of apples. Results showed that crown compounds used in this study were effective, both as inhibitors of the oxidation of phenolic compounds (PPO substrates) in model solutions and as inhibitors of enzyme discolorations of real systems (fresh-cut apples). In the earlier published papers (V UKOVI C 'et al., 1999) the synthesis of crown compound used in this study was presented

    In vitro sensitivity testing of minimally passaged and uncultured gliomas with TRAIL and/or chemotherapy drugs

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    TRAIL/Apo-2L has shown promise as an anti-glioma drug, based on investigations of TRAIL sensitivity in established glioma cell lines, but it is not known how accurately TRAIL signalling pathways of glioma cells in vivo are reproduced in these cell lines in vitro. To replicate as closely as possible the in vivo behaviour of malignant glioma cells, 17 early passage glioma cell lines and 5 freshly resected gliomas were exposed to TRAIL-based agents and/or chemotherapeutic drugs. Normal human hepatocytes and astrocytes and established glioma cell lines were also tested. Cross-linked TRAIL, but not soluble TRAIL, killed both normal cell types and cells from three tumours. Cells from only one glioma were killed by soluble TRAIL, although only inefficiently. High concentrations of cisplatin were lethal to glioma cells, hepatocytes and astrocytes. Isolated combinations of TRAIL and chemotherapy drugs were more toxic to particular gliomas than normal cells, but no combination was generally selective for glioma cells. This study highlights the widespread resistance of glioma cells to TRAIL-based agents, but suggests that a minority of high-grade glioma patients may benefit from particular combinations of TRAIL and chemotherapy drugs. In vitro sensitivity assays may help identify effective drug combinations for individual glioma patients
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