280 research outputs found

    N-Aryl-linked spirocyclic polymers for membrane separations of complex hydrocarbon mixtures

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    The fractionation of crude-oil mixtures through distillation is a large-scale, energy-intensive process. Membrane materials can avoid phase changes in such mixtures and thereby reduce the energy intensity of these thermal separations. With this application in mind, we created spirocyclic polymers with N-aryl bonds that demonstrated noninterconnected microporosity in the absence of ladder linkages. The resulting glassy polymer membranes demonstrated nonthermal membrane fractionation of light crude oil through a combination of class- and size-based “sorting” of molecules. We observed an enrichment of molecules lighter than 170 daltons corresponding to a carbon number of 12 or a boiling point less than 200°C in the permeate. Such scalable, selective membranes offer potential for the hybridization of energy-efficient technology with conventional processes such as distillation

    Randomised trial of glutamine and selenium supplemented parenteral nutrition for critically ill patients

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    Background: Mortality rates in the Intensive Care Unit and subsequent hospital mortality rates in the UK remain high. Infections in Intensive Care are associated with a 2–3 times increased risk of death. It is thought that under conditions of severe metabolic stress glutamine becomes "conditionally essential". Selenium is an essential trace element that has antioxidant and anti-inflammatory properties. Approximately 23% of patients in Intensive Care require parenteral nutrition and glutamine and selenium are either absent or present in low amounts. Both glutamine and selenium have the potential to influence the immune system through independent biochemical pathways. Systematic reviews suggest that supplementing parenteral nutrition in critical illness with glutamine or selenium may reduce infections and mortality. Pilot data has shown that more than 50% of participants developed infections, typically resistant organisms. We are powered to show definitively whether supplementation of PN with either glutamine or selenium is effective at reducing new infections in critically ill patients. Methods/design: 2 × 2 factorial, pragmatic, multicentre, double-blind, randomised controlled trial. The trial has an enrolment target of 500 patients. Inclusion criteria include: expected to be in critical care for at least 48 hours, aged 16 years or over, patients who require parenteral nutrition and are expected to have at least half their daily nutritional requirements given by that route. Allocation is to one of four iso-caloric, iso-nitrogenous groups: glutamine, selenium, both glutamine & selenium or no additional glutamine or selenium. Trial supplementation is given for up to seven days on the Intensive Care Unit and subsequent wards if practicable. The primary outcomes are episodes of infection in the 14 days after starting trial nutrition and mortality. Secondary outcomes include antibiotic usage, length of hospital stay, quality of life and cost-effectiveness. Discussion: To date more than 285 patients have been recruited to the trial from 10 sites in Scotland. Recruitment is due to finish in August 2008 with a further six months follow up. We expect to report the results of the trial in summer 2009. Trial registration: This trial is registered with the International Standard Randomised Controlled Trial Number system. ISRCTN87144826Not peer reviewedPublisher PD

    Dietary intakes of flavan-3-ols and cardiovascular health: a field synopsis using evidence mapping of randomized trials and prospective cohort studies

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    Background: There is considerable interest in the impact of increased flavan-3-ol intake on cardiovascular disease (CVD) and diabetes outcomes. Through evidence mapping, we determined the extent of the evidence base to initiate a future systematic review investigating the impact of flavan-3-ol intake on CVD and diabetes outcomes. Methods: We developed a research protocol, convened a technical expert panel (TEP) to refine the specific research questions, conducted a systematic search in multiple databases, double-screened abstracts and full-text articles, performed data extractions, and synthesized the data. We focused on randomized controlled trials (RCTs) and prospective cohort studies which assessed intakes of flavan-3-ol from foods, beverages, and supplement/extract sources on biomarkers and clinical outcomes of CVD and diabetes. Results: Of 257 eligible articles, 223 and 34 publications contributed to 226 RCTs and 39 prospective cohort studies, respectively. In RCTs, the most frequently studied interventions were cocoa-based products (23.2%); berries (16.1%); tea in the form of green tea (13.9%), black tea (7.2%), or unspecified tea (3.6%); and red wine (11.2%). Mean total flavan-3-ol intake was highest in the cocoa-based trials (618.7 mg/day) and lowest in the interventions feeding red wine (123.7 mg/day). The most frequently reported outcomes were intermediate biomarkers including serum lipid levels (63.4%), blood glucose (50.9%), blood pressure (50.8%), flow-mediated dilation (21.9%), and high-sensitivity C-reactive protein (21.9%). The included 34 prospective cohort studies predominantly examined exposures to flavan-3-ols (26%), cocoa-based products (23.2%), berries (16.1%), and green tea (13.9%) and CVD incidence and mortality. Conclusion: Through a systematic, evidence-based approach, evidence mapping on flavan-3-ol intake and CVD outcomes demonstrated sufficient data relating to flavan-3ol intake and biomarkers and clinical outcomes of CVD and diabetes. The current evidence base highlights the distribution of available data which both support the development of a future systematic review and identified the research need for future long-term RCTs

    Early intestinal Bacteroides fragilis colonisation and development of asthma

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    <p>Abstract</p> <p>Background</p> <p>The 'hygiene hypothesis' suggests that early exposure to microbes can be protective against atopic disease. The intestinal microbial flora could operate as an important postnatal regulator of the Th1/Th2 balance. The aim of the study was to investigate the association between early intestinal colonisation and the development of asthma in the first 3 years of life.</p> <p>Methods</p> <p>In a prospective birth cohort, 117 children were classified according to the Asthma Predictive Index. A positive index included wheezing during the first three years of life combined with eczema in the child in the first years of life or with a parental history of asthma. A faecal sample was taken at the age of 3 weeks and cultured on selective media.</p> <p>Results</p> <p>Asthma Predictive Index was positive in 26/117 (22%) of the children. The prevalence of colonisation with <it>Bacteroides fragilis </it>was higher at 3 weeks in index+ compared to index- children (64% vs. 34% p < 0,05). <it>Bacteroides fragilis </it>and <it>Total Anaerobes </it>counts at 3 weeks were significantly higher in children with a positive index as compared with those without. After adjusting for confounders a positive association was found between <it>Bacteroides fragilis </it>colonisation and Asthma Predictive Index (odds ratio: 4,4; confidence interval: 1,7 – 11,8).</p> <p>Conclusion</p> <p><it>Bacteroides fragilis </it>colonisation at age 3 weeks is an early indicator of possible asthma later in life. This study could provide the means for more accurate targeting of treatment and prevention and thus more effective and better controlled modulation of the microbial milieu.</p

    Oral Health in Women During Preconception and Pregnancy: Implications for Birth Outcomes and Infant Oral Health

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    The mouth is an obvious portal of entry to the body, and oral health reflects and influences general health and well being. Maternal oral health has significant implications for birth outcomes and infant oral health. Maternal periodontal disease, that is, a chronic infection of the gingiva and supporting tooth structures, has been associated with preterm birth, development of preeclampsia, and delivery of a small-for-gestational age infant. Maternal oral flora is transmitted to the newborn infant, and increased cariogenic flora in the mother predisposes the infant to the development of caries. It is intriguing to consider preconception, pregnancy, or intrapartum treatment of oral health conditions as a mechanism to improve women's oral and general health, pregnancy outcomes, and their children's dental health. However, given the relationship between oral health and general health, oral health care should be a goal in its own right for all individuals. Regardless of the potential for improved oral health to improve pregnancy outcomes, public policies that support comprehensive dental services for vulnerable women of childbearing age should be expanded so that their own oral and general health is safeguarded and their children's risk of caries is reduced. Oral health promotion should include education of women and their health care providers ways to prevent oral disease from occurring, and referral for dental services when disease is present

    Experimental Infection of Cynomolgus Macaques (Macaca fascicularis) with Aerosolized Monkeypox Virus

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    Monkeypox virus (MPXV) infection in humans results in clinical symptoms very similar to ordinary smallpox. Aerosol is a route of secondary transmission for monkeypox, and a primary route of smallpox transmission in humans. Therefore, an animal model for aerosol exposure to MPXV is needed to test medical countermeasures. To characterize the pathogenesis in cynomolgus macaques (Macaca fascicularis), groups of macaques were exposed to four different doses of aerosolized MPXV. Blood was collected the day before, and every other day after exposure and assessed for complete blood count (CBC), clinical chemistry analysis, and quantitative PCR. Macaques showed mild anorexia, depression, and fever on day 6 post-exposure. Lymphadenopathy, which differentiates monkeypox from smallpox, was observed in exposed macaques around day 6 post-exposure. CBC and clinical chemistries showed abnormalities similar to human monkeypox cases. Whole blood and throat swab viral loads peaked around day 10, and in survivors, gradually decreased until day 28 post-exposure. Survival was not dose dependent. As such, doses of 4×104 PFU, 1×105 PFU, or 1×106 PFU resulted in lethality for 70% of the animals, whereas a dose of 4×105 PFU resulted in 85% lethality. Overall, cynomolgus macaques exposed to aerosolized MPXV develop a clinical disease that resembles that of human monkeypox. These findings provide a strong foundation for the use of aerosolized MPXV exposure of cynomolgus macaques as an animal model to test medical countermeasures against orthopoxviruses

    Prader-Willi syndrome: A primer for clinicians

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    The advent of sensitive genetic testing modalities for the diagnosis of Prader-Willi syndrome has helped to define not only the phenotypic features of the syndrome associated with the various genotypes but also to anticipate clinical and psychological problems that occur at each stage during the life span. With advances in hormone replacement therapy, particularly growth hormone children born in circumstances where therapy is available are expected to have an improved quality of life as compared to those born prior to growth hormone

    Evaluation of a local government "shelter and van" intervention to improve safety and reduce alcohol-related harm.

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    Background: The entertainment precincts of cities, while contributing to local economies, need to be carefully managed to mitigate harms. Individual behaviours and government regulation have typically been the foci of interventions aimed at reducing alcohol-related harm. Little is known about how changes to the built environment might influence alcohol-related harms in these settings. The aim of this study was to explore how a public shelter and a volunteer-funded and staffed mobile van in a regional city influenced perceptions of safety and reduction in alcohol-related harm. Methods: An intrinsic case-study approach was used. Document reviews, qualitative interviews with 16 key informants (volunteers, licensees, police, local business owners, patrons, community members and security guards), observation, and secondary data analysis were conducted in 2016. A conceptual framework of the causative pathways linking the drivers of alcohol consumption with social and health outcomes was used to inform the analysis. Results: The shelter and van were frequently utilised but there was no significant association with a reduction in the proportion of alcohol-related hospital emergency department presentations or police incident reports. Occupational health and safety risks were identified for the volunteers which had no management plan. Conclusions: The findings highlight the challenge faced by local governments/authorities wanting to provide community-based interventions to complement other evidence-based approaches to reduce alcohol-related harm. Local governments/authorities with restricted regulatory oversight need to collaborate with key agencies for targeted upstream and evidence-based alcohol prevention and management interventions before investing resources. Such approaches are critical for improving community safety as well as health and social outcomes in communities at greatest risk of alcohol-related harm

    Free abdominal fluid without obvious solid organ injury upon CT imaging: an actual problem or simply over-diagnosing?

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    Whereas a non-operative approach for hemodynamically stable patients with free intraabdominal fluid in the presence of solid organ injury is generally accepted, the presence of free fluid in the abdomen without evidence of solid organ injury not only presents a challenge for the treating emergency physician but also for the surgeon in charge. Despite recent advances in imaging modalities, with multi-detector computed tomography (CT) (with or without contrast agent) usually the imaging method of choice, diagnosis and interpretation of the results remains difficult. While some studies conclude that CT is highly accurate and relatively specific at diagnosing mesenteric and hollow viscus injury, others studies deem CT to be unreliable. These differences may in part be due to the experience and the interpretation of the radiologist and/or the treating physician or surgeon
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