1,048 research outputs found

    'Unbearable suffering': a qualitative study on the perspectives of patients who request assistance in dying

    No full text
    BACKGROUND One of the objectives of medicine is to relieve patients' suffering. As a consequence, it is important to understand patients' perspectives of suffering and their ability to cope. However, there is poor insight into what determines their suffering and their ability to bear it. PURPOSE To explore the constituent elements of suffering of patients who explicitly request euthanasia or physician-assisted suicide (EAS) and to better understand unbearable suffering from the patients' perspective. PATIENTS AND METHODS A qualitative study using in-depth face-to-face interviews was conducted with 31 patients who had requested EAS. The grounded theory approach was used to analyse the data. RESULTS Medical, psycho-emotional, socio-environmental and existential themes contributed to suffering. Especially fatigue, pain, decline, negative feelings, loss of self, fear of future suffering, dependency, loss of autonomy, being worn out, being a burden, loneliness, loss of all that makes life worth living, hopelessness, pointlessness and being tired of living were constituent elements of unbearable suffering. Only patients with a psychiatric (co)diagnosis suffered unbearably all the time. CONCLUSIONS Unbearable suffering is the outcome of an intensive process that originates in the symptoms of illness and/or ageing. According to patients, hopelessness is an essential element of unbearable suffering. Medical and social elements may cause suffering, but especially when accompanied by psycho-emotional and existential problems suffering will become 'unbearable'. Personality characteristics and biographical aspects greatly influence the burden of suffering. Unbearable suffering can only be understood in the continuum of the patients' perspectives of the past, the present and expectations of the future.This study was supported by the Dutch Cancer Society (grant number KUN2007-03736)

    Modelling the influence of RKIP on the ERK signalling pathway using the stochastic process algebra PEPA

    Get PDF
    This paper examines the influence of the Raf Kinase Inhibitor Protein (RKIP) on the Extracellular signal Regulated Kinase (ERK) signalling pathway [5] through modelling in a Markovian process algebra, PEPA [11]. Two models of the system are presented, a reagent-centric view and a pathway-centric view. The models capture functionality at the level of subpathway, rather than at a molecular level. Each model affords a different perspective of the pathway and analysis. We demonstrate the two models to be formally equivalent using the timing-aware bisimulation defined over PEPA models and discuss the biological significance

    Diffusion, phase behavior and gelation in a two-dimensional layer of colloids in osmotic equilibrium with a polymer reservoir

    Get PDF
    The addition of enough non-adsorbing polymer to an otherwise stable colloidal suspension gives rise to a variety of phase behavior and kinetic arrest due to the depletion attraction induced between the colloids by the polymers. We report a study of these phenomena in a two-dimensional layer of colloids. The three-dimensional phenomenology of crystal-fluid coexistence is reproduced, but gelation takes a novel form, in which the strands in the gel structure are locally crystalline. We compare our findings with a previous simulation and theory, and find substantial agreement

    A comparison of collision cross section values obtained via travelling wave ion mobility-mass spectrometry and ultra high performance liquid chromatography-ion mobility-mass spectrometry : application to the characterisation of metabolites in rat urine

    Get PDF
    A comprehensive Collision Cross Section (CCS) library was obtained via Travelling Wave Ion Guide mobility measurements through direct infusion (DI). The library consists of CCS and Mass Spectral (MS) data in negative and positive ElectroSpray Ionisation (ESI) mode for 463 and 479 endogenous metabolites, respectively. For both ionisation modes combined, TWCCSN2 data were obtained for 542 non-redundant metabolites. These data were acquired on two different ion mobility enabled orthogonal acceleration QToF MS systems in two different laboratories, with the majority of the resulting TWCCSN2 values (from detected compounds) found to be within 1% of one another. Validation of these results against two independent, external TWCCSN2 data sources and predicted TWCCSN2 values indicated to be within 1-2% of these other values. The same metabolites were then analysed using a rapid reversed-phase ultra (high) performance liquid chromatographic (U(H)PLC) separation combined with IM and MS (IM-MS) thus providing retention time (tr), m/z and TWCCSN2 values (with the latter compared with the DI-IM-MS data). Analytes for which TWCCSN2 values were obtained by U(H)PLC-IM-MS showed good agreement with the results obtained from DI-IM-MS. The repeatability of the TWCCSN2 values obtained for these metabolites on the different ion mobility QToF systems, using either DI or LC, encouraged the further evaluation of the U(H)PLC-IM-MS approach via the analysis of samples of rat urine, from control and methotrexate-treated animals, in order to assess the potential of the approach for metabolite identification and profiling in metabolic phenotyping studies. Based on the database derived from the standards 63 metabolites were identified in rat urine, using positive ESI, based on the combination of tr, TWCCSN2 and MS data.</p

    Human platelets mediate iron release from transferrin by adenine nucleotide-dependent and -independent mechanisms

    Full text link
    We assessed the ability of platelet sonicates and mediators secreted by unstimulated and thrombin-stimulated platelets to facilitate the release of iron from transferrin. Platelet sonicates and platelet conditioned media potentiated the release of iron from transferrin. The rate of release of iron was dependent on the pH of the reaction and amount of platelet sample added. Conditioned media from thrombin-stimulated platelets was more effective in mediating the release of iron from transferrin than was conditioned media from unstimulated cells. The rate of iron released from transferrin following addition of ATP and ADP in amounts equivalent to that present in platelet conditioned media was significantly less than the rate of iron released following the addition of conditioned media from platelets. Depletion of ATP and ADP in platelet conditioned media by incubation with apyrase only partially inhibited their ability to enhance the rate of iron release from transferrin. These observations indicate that platelets enhance the release of iron from transferrin by adenine nucleotide-dependent and -independent mechanisms. These observations are consistent with the hypothesis that platelets promote oxidant-induced tissue injury at sights of inflammation secondary to their ability to enhance the local release of iron from transferrin.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28084/1/0000530.pd

    IRIS Burst Spectra Co-Spatial To A Quiet-Sun Ellerman-Like Brightening

    Get PDF
    Ellerman bombs (EBs) have been widely studied over the past two decades; however, only recently have counterparts of these events been observed in the quiet-Sun. The aim of this article is to further understand small-scale quiet-Sun Ellerman-like brightenings (QSEBs) through research into their spectral signatures, including investigating whether the hot signatures associated with some EBs are also visible co-spatial to any QSEBs. We combine Hα\alpha and Ca II 85428542 \AA\ line scans at the solar limb with spectral and imaging data sampled by the Interface Region Imaging Spectrograph (IRIS). Twenty one QSEBs were identified with average lifetimes, lengths, and widths measured to be around 120120 s, 0.630.63", and 0.350.35", respectively. Three of these QSEBs displayed clear repetitive flaring through their lifetimes, comparable to the behaviour of EBs in Active Regions (ARs). Two QSEBs in this sample occurred co-spatial with increased emission in SDO/AIA 16001600 \AA\ and IRIS slit-jaw imager 14001400 \AA\ data, however, these intensity increases were smaller than reported co-spatial to EBs. One QSEB was also sampled by the IRIS slit during its lifetime, displaying increases in intensity in the Si IV 13931393 \AA\ and Si IV 14031403 \AA\ cores as well as the C II and Mg II line wings, analogous to IRIS bursts (IBs). Using RADYN simulations, we are unable to reproduce the observed QSEB Hα\alpha and Ca II 85428542 \AA\ line profiles leaving the question of the temperature stratification of QSEBs open. Our results imply that some QSEBs could be heated to Transition Region temperatures, suggesting that IB profiles should be observed throughout the quiet-Sun

    280 GHz Focal Plane Unit Design and Characterization for the SPIDER-2 Suborbital Polarimeter

    Get PDF
    We describe the construction and characterization of the 280 GHz bolometric focal plane units (FPUs) to be deployed on the second flight of the balloon-borne SPIDER instrument. These FPUs are vital to SPIDER's primary science goal of detecting or placing an upper limit on the amplitude of the primordial gravitational wave signature in the cosmic microwave background (CMB) by constraining the B-mode contamination in the CMB from Galactic dust emission. Each 280 GHz focal plane contains a 16 x 16 grid of corrugated silicon feedhorns coupled to an array of aluminum-manganese transition-edge sensor (TES) bolometers fabricated on 150 mm diameter substrates. In total, the three 280 GHz FPUs contain 1,530 polarization sensitive bolometers (765 spatial pixels) optimized for the low loading environment in flight and read out by time-division SQUID multiplexing. In this paper we describe the mechanical, thermal, and magnetic shielding architecture of the focal planes and present cryogenic measurements which characterize yield and the uniformity of several bolometer parameters. The assembled FPUs have high yields, with one array as high as 95% including defects from wiring and readout. We demonstrate high uniformity in device parameters, finding the median saturation power for each TES array to be ~3 pW at 300 mK with a less than 6% variation across each array at one standard deviation. These focal planes will be deployed alongside the 95 and 150 GHz telescopes in the SPIDER-2 instrument, slated to fly from McMurdo Station in Antarctica in December 2018
    corecore