623 research outputs found

    The Effect of Different Interfaces and Confinement on the Structure of the Ionic Liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide Entrapped in Cationic and Anionic Reverse Micelles.

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    The behavior of the ionic liquid (IL) 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([bmim][Tf 2N]) entrapped in two reverse micelles (RMs) formed in an aromatic solvent as dispersant pseudophase: [bmim][Tf 2N]/benzyl-n-hexadecyldimethylammonium chloride (BHDC)/chlorobenzene and [bmim][Tf 2N]/sodium 1,4-bis-2- ethylhexylsulfosuccinate (AOT)/chlorobenzene, was investigated using dynamic light scattering (DLS), FT-IR and 1H NMR spectroscopies. DLS results reveal the formation of RMs containing [bmim][Tf 2N] as a polar component since the droplet size values increase as the W s (W s = [[bmim][Tf 2N]]/[surfactant]) increases. Furthermore, it shows that the RMs consist of discrete spherical and non-interacting droplets of [bmim][Tf 2N] stabilized by the surfactants. Important differences in the structure of [bmim][Tf 2N] entrapped inside BHDC RMs, in comparison with the neat IL, are observed from the FT-IR and 1H NMR measurements. The electrostatic interactions between anions and cations from [bmim][Tf 2N] and BHDC determine the solvent structure encapsulated inside the nano-droplets. It seems that the IL structure is disrupted due to the electrostatic interaction between the [Tf 2N] - and the cationic BHDC polar head (BHD +) giving a high ion pair degree between BHD + and [Tf 2N] - at a low IL content. On the other hand, for the AOT RMs there is no evidence of strong IL-surfactant interaction. The electrostatic interaction between the SO 3 - group and the Na + counterion in AOT seems to be stronger than the possible [bmim] +-SO 3 - interaction at the interface. Thus, the structure of [bmim][Tf 2N] encapsulated is not particularly disrupted by the anionic surfactant at all W s studied, in contrast to the BHDC RM results. Nevertheless, there is evidence of confinement in the AOT RMs because the [bmim] +-[Tf 2N] - interaction is stronger than in bulk solution. Thus, the IL is more associated upon confinement. Our results reveal that the [bmim][Tf 2N] structure can be modified in a different manner inside RMs by varying the kind of surfactant used to create the RMs and the IL content (W s). These facts can be very important if these media are used as nanoreactors because unique microenvironments can be easily created by simply changing the RM components and W s.Fil: Ferreyra, DarĂ­o David. Universidad Nacional de RĂ­o Cuarto. Facultad de Ciencias Exactas FisicoquĂ­micas y Naturales. Departamento de QuĂ­mica; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - CĂłrdoba; ArgentinaFil: Correa, Nestor Mariano. Universidad Nacional de RĂ­o Cuarto. Facultad de Ciencias Exactas FisicoquĂ­micas y Naturales. Departamento de QuĂ­mica; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - CĂłrdoba; ArgentinaFil: Silber, Juana J.. Universidad Nacional de RĂ­o Cuarto. Facultad de Ciencias Exactas FisicoquĂ­micas y Naturales. Departamento de QuĂ­mica; ArgentinaFil: Falcone, Ruben Dario. Universidad Nacional de RĂ­o Cuarto. Facultad de Ciencias Exactas FisicoquĂ­micas y Naturales. Departamento de QuĂ­mica; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - CĂłrdoba; Argentin

    Changes in the prevalence, treatment and control of hypertension in Germany? : a clinical-epidemiological study of 50.000 primary care patients

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    INTRODUCTION: Medical societies have developed guidelines for the detection, treatment and control of hypertension (HTN). Our analysis assessed the extent to which such guidelines were implemented in Germany in 2003 and 2001. METHODS: Using standardized clinical diagnostic and treatment appraisal forms, blood pressure levels and patient questionnaires for 55,518 participants from the cross-sectional Targets and Essential Data for Commitment of Treatment (DETECT) study (2003) were analyzed. Physician's diagnosis of hypertension (HTN(doc)) was defined as coding hypertension in the clinical appraisal questionnaire. Alternative definitions used were physician's diagnosis or the patient's self-reported diagnosis of hypertension (HTN(doc,pat)), physician's or patient's self-reported diagnosis or a BP measurement with a systolic BP≄140 mmHg and/or a diastolic BP≄90 (HTN(doc,pat,bp)) and diagnosis according to the National Health and Nutrition Examination Survey (HTN(NHANES)). The results were compared with the similar German HYDRA study to examine whether changes had occurred in diagnosis, treatment and adequate blood pressure control (BP below 140/90 mmHg) since 2001. Factors associated with pharmacotherapy and control were determined. RESULTS: The overall prevalence rate for hypertension was 35.5% according to HTN(doc) and 56.0% according to NHANES criteria. Among those defined by NHANES criteria, treatment and control rates were 56.0% and 20.3% in 2003, and these rates had improved from 55.3% and 18.0% in 2001. Significant predictors of receiving antihypertensive medication were: increasing age, female sex, obesity, previous myocardial infarction and the prevalence of comorbid conditions such as coronary heart disease (CHD), hyperlipidemia and diabetes mellitus (DM). Significant positive predictors of adequate blood pressure control were CHD and antihypertensive medication. Inadequate control was associated with increasing age, male sex and obesity. CONCLUSIONS: Rates of treated and controlled hypertension according to NHANES criteria in DETECT remained low between 2001 and 2003, although there was some minor improvement

    Self-renewal of single mouse hematopoietic stem cells is reduced by JAK2V617F without compromising progenitor cell expansion

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    Recent descriptions of significant heterogeneity in normal stem cells and cancers have altered our understanding of tumorigenesis, emphasizing the need to understand how single stem cells are subverted to cause tumors. Human myeloproliferative neoplasms (MPNs) are thought to reflect transformation of a hematopoietic stem cell (HSC) and the majority harbor an acquired V617F mutation in the JAK2 tyrosine kinase, making them a paradigm for studying the early stages of tumor establishment and progression. The consequences of activating tyrosine kinase mutations for stem and progenitor cell behavior are unclear. In this article, we identify a distinct cellular mechanism operative in stem cells. By using conditional knock-in mice, we show that the HSC defect resulting from expression of heterozygous human JAK2V617F is both quantitative (reduced HSC numbers) and qualitative (lineage biases and reduced self-renewal per HSC). The defect is intrinsic to individual HSCs and their progeny are skewed toward proliferation and differentiation as evidenced by single cell and transplantation assays. Aged JAK2V617F show a more pronounced defect as assessed by transplantation, but mice that transform reacquire competitive self-renewal ability. Quantitative analysis of HSC-derived clones was used to model the fate choices of normal and JAK2-mutant HSCs and indicates that JAK2V617F reduces self-renewal of individual HSCs but leaves progenitor expansion intact. This conclusion is supported by paired daughter cell analyses, which indicate that JAK2-mutant HSCs more often give rise to two differentiated daughter cells. Together these data suggest that acquisition of JAK2V617F alone is insufficient for clonal expansion and disease progression and causes eventual HSC exhaustion. Moreover, our results show that clonal expansion of progenitor cells provides a window in which collaborating mutations can accumulate to drive disease progression. Characterizing the mechanism(s) of JAK2V617F subclinical clonal expansions and the transition to overt MPNs will illuminate the earliest stages of tumor establishment and subclone competition, fundamentally shifting the way we treat and manage cancers

    Changing and unchanging values in the world of the future, November 8, 9, and 10, 2001

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    This repository item contains a single issue of the Pardee Conference Series, a publication series that began publishing in 2006 by the Boston University Frederick S. Pardee Center for the Study of the Longer-Range Future. This was the Center's Inaugural Conference that took place during November 8, 9, and 10, 2001. Organized by David Fromkin, Director Frederick S. Pardee Center for the Study of the Longer-Range Future. Co-Sponsored by Boston University and Carnegie Council on Ethics and International Affairs.This conference brought together a discussion of different perspectives on what future paradigm shifts will look like – in government, in foreign policy, in what constitutes “classics,” in economic and religious modes, and changes in the interaction between these values. The conference agreed that today’s Western society values democracy, constitutionalism, liberalism, rule of law, open society, and market economy. These are not contingent upon one another and may change. But the “needs and aspirations” of humanity will at their most essential core remain the same. The amount and type of power given to governments is not a fixed thing, and developments in the meaning of democracy and how it is achieved may illustrate this

    Focal Plate Structure Alignment of the Dark Energy Spectroscopic Instrument

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    The Dark Energy Spectroscopic Instrument (DESI) is under construction to measure the expansion history of the universe using the Baryon Acoustic Oscillation (BAO) technique. The spectra of 35 million galaxies and quasars over 14000 deg214000 \,\text{deg}^2 will be measured during the life of the experiment. A new prime focus corrector for the KPNO Mayall telescope will deliver light to 5000 robotically positioned optic fibres. The fibres in turn feed ten broadband spectrographs. Proper alignment of focal plate structure, mainly consisting of a focal plate ring (FPR) and ten focal plate petals (FPP), is crucial in ensuring minimal loss of light in the focal plane. A coordinate measurement machine (CMM) metrology-based approach to alignment requires comprehensive characterisation of critical dimensions of the petals and the ring, all of which were 100% inspected. The metrology data not only served for quality assurance (QA), but also, with careful modelling of geometric transformations, informed the initial choice of integration accessories such as gauge blocks, pads, and shims. The integrated focal plate structure was inspected again on a CMM, and each petal was adjusted according to the updated focal plate metrology data until all datums were extremely close to nominal positions and optical throughput nearly reached the theoretically best possible value. This paper presents our metrology and alignment methodology and complete results for twelve official DESI petals. The as-aligned, total RMS optical throughput for 6168 positioner holes of twelve production petals was indirectly measured to be 99.88±0.12%99.88 \pm 0.12 \%, well above the 99.5% project requirement. The successful alignment fully demonstrated the wealth of data, reproducibility, and micron-level precision made available by our CMM metrology-based approach.Comment: 17 pages, 10 figures, 3 table

    Position, swimming direction and group size of fin whales (Balaenoptera physalus) in the presence of a fast-ferry in the Bay of Biscay

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    We analyze group size, swimming direction and the orientation of fin whales relative to a fast ferry in the Bay of Biscay. Fin whale groups (≄3 individuals) were on average closer to the vessel than single individuals and pairs (F1,114 = 4.94, p = 0.028) and were more often observed within a high-risk angle ahead of the ferry (binomial probability: p = 7.60 × 10−11). Also, small groups tend to swim in the opposite direction (heading of 180°) of the ferry at the starboard side (binomial test: p = 6.86 × 10−5) and at the portside (binomial test: p = 0.0156). These findings provide valuable information to improve shipping management procedures in areas at high risk for collisions

    Phenoconversion from probable rapid eye movement sleep behavior disorder to mild cognitive impairment to dementia in a population-based sample

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    © 2017 The Authors Introduction Rapid eye movement sleep behavior disorder (RBD) is strongly associated with synucleinopathies. In 2012, we reported an increased risk of mild cognitive impairment (MCI) and Parkinson disease (PD) in cognitively normal Olmsted County, Minnesota, residents, aged 70 to 89 years with probable RBD. Here, we examine their progression to dementia and other neurodegenerative phenotypes. Methods Fifteen participants with RBD who were diagnosed with either MCI or PD were longitudinally followed, and their subsequent clinical courses were reviewed. Results Over 6.4 ± 2.9 years, six of the 14 participants with MCI developed additional neurodegenerative signs, five of whom had Lewy body disease features. Four of them progressed to dementia at a mean age 84.8 ± 4.9 years, three of whom met the criteria for probable dementia with Lewy bodies. One subject with PD developed MCI, but not dementia. Discussion Our findings from the population-based sample of Olmsted County, Minnesota, residents suggest that a substantial number of RBD patients tend to develop overt synucleinopathy features over time, and RBD patients who develop MCI and subsequent dementia have clinical features most consistent with dementia with Lewy bodies
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