98 research outputs found

    The practice of palliative sedation in the Netherlands after the launch of the national guideline

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    Palliative sedation is a medical intervention aimed at relieving intractable suff ering by inducing decreased awareness of symptoms. It is typically considered a palliative option for patients suff ering unbearably in the last days of life. The estimated frequency of palliative sedation varies considerably in scientifi c literature, partly due to diff erences in defi nition and research setting and diff erences in terminology. Whereas in the English medical scientifi c literature the fi rst descriptions of palliative sedation referred to ‘terminal sedation’, in Dutch medical literature palliative sedation was fi rst described as ‘deep sedation in the dying phase’. Although terminology still varies – e.g. continuous deep sedation6, continuous sedation until death, continuous deep sedation until death, continuous sedation at the end of life, palliative sedation at the end of life, palliative sedation therapy, palliative sedation to unconsciousness, terminal sedation, continuous palliative sedation – the most frequently used general term for this treatment in the literature nowadays is palliative sedation

    What do near-term observations tell us about long-term developments in greenhouse gas emissions? A letter

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    Long-term scenarios developed by integrated assessment models are used in climate research to provide an indication of plausible long-term emissions of greenhouse gases and other radiatively active substances based on developments in the global energy system, land-use and the emissions associated with these systems The phenomena that determine these long-term developments (several decades or even centuries) are very different than those that operate on a shorter time-scales (a few years) Nevertheless, in the literature, we still often find direct comparisons between short-term observations and long-term developments that do not take into account the differing dynamics over these time scales In this letter, we discuss some of the differences between the factors that operate in the short term and those that operate in the long term We use long-term historical emissions trends to show that short-term observations are very poor indicators of long-term future emissions developments Based on this, we conclude that the performance of long-term scenarios should be evaluated against the appropriate, corresponding long-term variables and trends The research community may facilitate this by developing appropriate data sets and protocols that can be used to test the performance of long-term scenarios and the models that produce the

    The effect of annealing time on the structural and optical properties of ZnAl2O4:0.01% Cr3+ nanophosphor prepared via sol-gel method

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    Zinc aluminate (ZnAl2O4) host and 0.01% Cr3+ doped were successfully prepared using the sol–gel method. The annealing time (AT) was varied in the range of 0.5–19 h. The x-ray diffraction results showed that the AT does not affect the crystal structure of the prepared powders. Scanning electron microscopy (SEM) results showed that the morphology of the prepared nanophosphors was influenced by the AT. Energy dispersive x-ray spectroscopy (EDS) confirmed the homogeneous distribution of the constituent elements. Transmission electron microscopy (TEM) suggested that the average crystallites sizes of the ZnAl2O4 to be ~20 nm. Ultraviolet–visible (UV–Vis) spectroscopy results revealed that the bandgap (E g) of the prepared nanophosphor can be tuned by varying the AT. The emission peak at 390 nm is attributed to the intrinsic defects within the host material bandgap. The emission peak at 572 nm is attributed to both contribution from the host and Cr3+ (4T1 → 4A2) transition. The maximum PL intensity was observed from the samples annealed for 3 h. The International Commission on Illumination (CIE) chromaticity diagram showed a slight shift on the blue emission with an increase in AT.http://link.springer.com/journal/116642019-01-30hj2018Physic

    Regge description of two pseudoscalar meson production in antiproton-proton annihilation

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    A Regge-inspired model is used to discuss the hard exclusive two-body hadronic reactions (pbar p ----> pi+ pi-, pi0 pi0, K+ K-, Kbar0 K0) for the FAIR facility project at GSI with the Panda detector. The comparison between the differential cross sections predictions and the available data is shown to determine the values of the few parameters of the model.Comment: 9 pages, 13 figure

    Semileptonic decay constants of octet baryons in the chiral quark-soliton model

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    Based on the recent study of the magnetic moments and axial constants within the framework of the chiral quark-soliton model, we investigate the baryon semileptonic decay constants (f1,f2)(f_1,f_2) and (g1,g2)(g_1, g_2). Employing the relations between the diagonal transition matrix elements and off-diagonal ones in the vector and axial-vector channels, we obtain the ratios of baryon semileptonic decay constants f2/f1f_2/f_1 and g1/f1g_1/f_1. The F/DF/D ratio is also discussed and found that the value predicted by the present model naturally lies between that of the Skyrme model and that of the nonrelativistic quark model. The singlet axial constant gA(0)g^{(0)}_A can be expressed in terms of the F/DF/D ratio and gA(3)g^{(3)}_A in the present model and turns out to be small. The results are compared with available experimental data and found to be in good agreement with them. In addition, the induced pseudotensor coupling constants g2/f1g_2/f_1 are calculated, the SU(3) symmetry breaking being considered. The results indicate that the effect of SU(3) symmetry breaking might play an important role for some decay modes in hyperon semileptonic decay.Comment: 16 pages, RevTeX is used. No figure. Accepted for publication in Phys. Rev.

    Additional evidence on serological correlates of protection against measles: An observational cohort study among once vaccinated children exposed to measles

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    To assess correlates of protection against measles and against subclinical measles virus (MV) infection, we recruited once-vaccinated children from geographic regions associated with increased MV circulation and/or at schools with low vaccination coverage in the Netherlands. Paired blood samples were collected shortly after onset of the measles outbreak and after the outbreak. A questionnaire was used to document the likelihood of exposure to MV and occurrence of measles-like symptoms. All blood samples were tested for MV-specific antibodies with five different assays. Correlates of protection were assessed by considering the lowest neutralizing antibody levels in children without MV infection, and by ROC analyses. Among 91 participants, two seronegative children (2%) developed measles, and an additional 19 (23%) experienced subclinical MV infection. The correlate of protection against measles was lower than 0.345 IU/mL. We observed a decreasing attack rate of subclinical MV infection with increasing levels of specific antibodies until 2.1 IU/mL, above which no subclinical MV infections were detected. The ROC analyses found a correlate of protection of 1.71 IU/mL (95% CI 1.01–2.11) for subclinical MV infection. Our correlates of protection were consistent with previous estimates. This information supports the analyses of serosurveys to detect immunity gaps that require targeted intervention strategies

    Low Q^2 Jet Production at HERA and Virtual Photon Structure

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    The transition between photoproduction and deep-inelastic scattering is investigated in jet production at the HERA ep collider, using data collected by the H1 experiment. Measurements of the differential inclusive jet cross-sections dsigep/dEt* and dsigmep/deta*, where Et* and eta* are the transverse energy and the pseudorapidity of the jets in the virtual photon-proton centre of mass frame, are presented for 0 < Q2 < 49 GeV2 and 0.3 < y < 0.6. The interpretation of the results in terms of the structure of the virtual photon is discussed. The data are best described by QCD calculations which include a partonic structure of the virtual photon that evolves with Q2.Comment: 20 pages, 5 Figure

    Hadron Production in Diffractive Deep-Inelastic Scattering

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    Characteristics of hadron production in diffractive deep-inelastic positron-proton scattering are studied using data collected in 1994 by the H1 experiment at HERA. The following distributions are measured in the centre-of-mass frame of the photon dissociation system: the hadronic energy flow, the Feynman-x (x_F) variable for charged particles, the squared transverse momentum of charged particles (p_T^{*2}), and the mean p_T^{*2} as a function of x_F. These distributions are compared with results in the gamma^* p centre-of-mass frame from inclusive deep-inelastic scattering in the fixed-target experiment EMC, and also with the predictions of several Monte Carlo calculations. The data are consistent with a picture in which the partonic structure of the diffractive exchange is dominated at low Q^2 by hard gluons.Comment: 16 pages, 6 figures, submitted to Phys. Lett.

    Measurement of Leading Proton and Neutron Production in Deep Inelastic Scattering at HERA

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    Deep--inelastic scattering events with a leading baryon have been detected by the H1 experiment at HERA using a forward proton spectrometer and a forward neutron calorimeter. Semi--inclusive cross sections have been measured in the kinematic region 2 <= Q^2 <= 50 GeV^2, 6.10^-5 <= x <= 6.10^-3 and baryon p_T <= MeV, for events with a final state proton with energy 580 <= E' <= 740 GeV, or a neutron with energy E' >= 160 GeV. The measurements are used to test production models and factorization hypotheses. A Regge model of leading baryon production which consists of pion, pomeron and secondary reggeon exchanges gives an acceptable description of both semi-inclusive cross sections in the region 0.7 <= E'/E_p <= 0.9, where E_p is the proton beam energy. The leading neutron data are used to estimate for the first time the structure function of the pion at small Bjorken--x.Comment: 30 pages, 9 figures, 2 tables, submitted to Eur. Phys.

    Measurement of D* Meson Cross Sections at HERA and Determination of the Gluon Density in the Proton using NLO QCD

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    With the H1 detector at the ep collider HERA, D* meson production cross sections have been measured in deep inelastic scattering with four-momentum transfers Q^2>2 GeV2 and in photoproduction at energies around W(gamma p)~ 88 GeV and 194 GeV. Next-to-Leading Order QCD calculations are found to describe the differential cross sections within theoretical and experimental uncertainties. Using these calculations, the NLO gluon momentum distribution in the proton, x_g g(x_g), has been extracted in the momentum fraction range 7.5x10^{-4}< x_g <4x10^{-2} at average scales mu^2 =25 to 50 GeV2. The gluon momentum fraction x_g has been obtained from the measured kinematics of the scattered electron and the D* meson in the final state. The results compare well with the gluon distribution obtained from the analysis of scaling violations of the proton structure function F_2.Comment: 27 pages, 9 figures, 2 tables, submitted to Nucl. Phys.
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