41 research outputs found

    Epidemic and Nonepidemic Multidrug-Resistant Enterococcus faecium

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    The epidemiology of vancomycin-resistant Enterococcus faecium (VREF) in Europe is characterized by a large community reservoir. In contrast, nosocomial outbreaks and infections (without a community reservoir) characterize VREF in the United States. Previous studies demonstrated host-specific genogroups and a distinct genetic lineage of VREF associated with hospital outbreaks, characterized by the variant esp-gene and a specific allele-type of the purK housekeeping gene (purK1). We investigated the genetic relatedness of vanA VREF (n=108) and vancomycin-susceptible E. faecium (VSEF) (n=92) from different epidemiologic sources by genotyping, susceptibility testing for ampicillin, sequencing of purK1, and testing for presence of esp. Clusters of VSEF fit well into previously described VREF genogroups, and strong associations were found between VSEF and VREF isolates with resistance to ampicillin, presence of esp, and purK1. Genotypes characterized by presence of esp, purK1, and ampicillin resistance were most frequent among outbreak-associated isolates and almost absent among community surveillance isolates. Vancomycin-resistance was not specifically linked to genogroups. VREF and VSEF from different epidemiologic sources are genetically related; evidence exists for nosocomial selection of a subtype of E. faecium, which has acquired vancomycin-resistance through horizontal transfer

    CMB Telescopes and Optical Systems

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    The cosmic microwave background radiation (CMB) is now firmly established as a fundamental and essential probe of the geometry, constituents, and birth of the Universe. The CMB is a potent observable because it can be measured with precision and accuracy. Just as importantly, theoretical models of the Universe can predict the characteristics of the CMB to high accuracy, and those predictions can be directly compared to observations. There are multiple aspects associated with making a precise measurement. In this review, we focus on optical components for the instrumentation used to measure the CMB polarization and temperature anisotropy. We begin with an overview of general considerations for CMB observations and discuss common concepts used in the community. We next consider a variety of alternatives available for a designer of a CMB telescope. Our discussion is guided by the ground and balloon-based instruments that have been implemented over the years. In the same vein, we compare the arc-minute resolution Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT). CMB interferometers are presented briefly. We conclude with a comparison of the four CMB satellites, Relikt, COBE, WMAP, and Planck, to demonstrate a remarkable evolution in design, sensitivity, resolution, and complexity over the past thirty years.Comment: To appear in: Planets, Stars and Stellar Systems (PSSS), Volume 1: Telescopes and Instrumentatio

    Postmenopausal hormones and sleep quality in the elderly: a population based study

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    <p>Abstract</p> <p>Background</p> <p>Sleep disturbance and insomnia are commonly reported by postmenopausal women. However, the relationship between hormone therapy (HT) and sleep disturbances in postmenopausal community-dwelling adults is understudied. Using data from the multicenter Study of Osteoporotic Fractures (SOF), we tested the relationship between HT and sleep-wake estimated from actigraphy.</p> <p>Methods</p> <p>Sleep-wake was ascertained by wrist actigraphy in 3,123 women aged 84 ± 4 years (range 77-99) from the Study of Osteoporotic Fractures (SOF). This sample represents 30% of the original SOF study and 64% of participants seen at this visit. Data were collected for a mean of 4 consecutive 24-hour periods. Sleep parameters measured objectively included total sleep time, sleep efficiency (SE), sleep latency, wake after sleep onset (WASO), and nap time. All analyses were adjusted for potential confounders (age, clinic site, race, BMI, cognitive function, physical activity, depression, anxiety, education, marital status, age at menopause, alcohol use, prior hysterectomy, and medical conditions).</p> <p>Results</p> <p>Actigraphy measurements were available for 424 current, 1,289 past, and 1,410 never users of HT. Women currently using HT had a shorter WASO time (76 vs. 82 minutes, P = 0.03) and fewer long-wake (≥ 5 minutes) episodes (6.5 vs. 7.1, P = 0.004) than never users. Past HT users had longer total sleep time than never users (413 vs. 403 minutes, P = 0.002). Women who never used HT had elevated odds of SE <70% (OR,1.37;95%CI,0.98-1.92) and significantly higher odds of WASO ≥ 90 minutes (OR,1.37;95%CI,1.02-1.83) and ≥ 8 long-wake episodes (OR,1.58;95%CI,1.18-2.12) when compared to current HT users.</p> <p>Conclusions</p> <p>Postmenopausal women currently using HT had improved sleep quality for two out of five objective measures: shorter WASO and fewer long-wake episodes. The mechanism behind these associations is not clear. For postmenopausal women, starting HT use should be considered carefully in balance with other risks since the vascular side-effects of hormone replacement may exceed its beneficial effects on sleep.</p

    Tools and techniques for solvent selection: green solvent selection guides

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    Driven by legislation and evolving attitudes towards environmental issues, establishing green solvents for extractions, separations, formulations and reaction chemistry has become an increasingly important area of research. Several general purpose solvent selection guides have now been published with the aim to reduce use of the most hazardous solvents. This review serves the purpose of explaining the role of these guides, highlighting their similarities and differences. How they can be used most effectively to enhance the greenness of chemical processes, particularly in laboratory organic synthesis and the pharmaceutical industry, is addressed in detail

    Three wound-dressing strategies to reduce surgical site infection after abdominal surgery: the Bluebelle feasibility study and pilot RCT

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    BACKGROUND: Surgical site infection (SSI) affects up to 20% of people with a primary closed wound after surgery. Wound dressings may reduce SSI. OBJECTIVE: To assess the feasibility of a multicentre randomised controlled trial (RCT) to evaluate the effectiveness and cost-effectiveness of dressing types or no dressing to reduce SSI in primary surgical wounds. DESIGN: Phase A - semistructured interviews, outcome measure development, practice survey, literature reviews and value-of-information analysis. Phase B - pilot RCT with qualitative research and questionnaire validation. Patients and the public were involved. SETTING: Usual NHS care. PARTICIPANTS: Patients undergoing elective/non-elective abdominal surgery, including caesarean section. INTERVENTIONS: Phase A - none. Phase B - simple dressing, glue-as-a-dressing (tissue adhesive) or 'no dressing'. MAIN OUTCOME MEASURES: Phase A - pilot RCT design; SSI, patient experience and wound management questionnaires; dressing practices; and value-of-information of a RCT. Phase B - participants screened, proportions consented/randomised; acceptability of interventions; adherence; retention; validity and reliability of SSI measure; and cost drivers. DATA SOURCES: Phase A - interviews with patients and health-care professionals (HCPs), narrative data from published RCTs and data about dressing practices. Phase B - participants and HCPs in five hospitals. RESULTS: Phase A - we interviewed 102 participants. HCPs interpreted 'dressing' variably and reported using available products. HCPs suggested practical/clinical reasons for dressing use, acknowledged the weak evidence base and felt that a RCT including a 'no dressing' group was acceptable. A survey showed that 68% of 1769 wounds (727 participants) had simple dressings and 27% had glue-as-a-dressing. Dressings were used similarly in elective and non-elective surgery. The SSI questionnaire was developed from a content analysis of existing SSI tools and interviews, yielding 19 domains and 16 items. A main RCT would be valuable to the NHS at a willingness to pay of £20,000 per quality-adjusted life-year. Phase B - from 4 March 2016 to 30 November 2016, we approached 862 patients for the pilot RCT; 81.1% were eligible, 59.4% consented and 394 were randomised (simple, n = 133; glue, n = 129; no dressing, n = 132); non-adherence was 3 out of 133, 8 out of 129 and 20 out of 132, respectively. SSI occurred in 51 out of 281 participants. We interviewed 55 participants. All dressing strategies were acceptable to stakeholders, with no indication that adherence was problematic. Adherence aids and patients' understanding of their allocated dressing appeared to be key. The SSI questionnaire response rate overall was 67.2%. Items in the SSI questionnaire fitted a single scale, which had good reliability (test-retest and Cronbach's alpha of > 0.7) and diagnostic accuracy (c-statistic = 0.906). The key cost drivers were hospital appointments, dressings and redressings, use of new medicines and primary care appointments. LIMITATIONS: Multiple activities, often in parallel, were challenging to co-ordinate. An amendment took 4 months, restricting recruitment to the pilot RCT. Only 67% of participants completed the SSI questionnaire. We could not implement photography in theatres. CONCLUSIONS: A main RCT of dressing strategies is feasible and would be valuable to the NHS. The SSI questionnaire is sufficiently accurate to be used as the primary outcome. A main trial with three groups (as in the pilot) would be valuable to the NHS, using a primary outcome of SSI at discharge and patient-reported SSI symptoms at 4-8 weeks. TRIAL REGISTRATION: Phase A - Current Controlled Trials ISRCTN06792113; Phase B - Current Controlled Trials ISRCTN49328913. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 39. See the NIHR Journals Library website for further project information. Funding was also provided by the Medical Research Council ConDuCT-II Hub (reference number MR/K025643/1)
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