| 1. |
- Schael, S., et al.
(författare)
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Electroweak measurements in electron positron collisions at W-boson-pair energies at LEP
- 2013
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Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 532:4, s. 119-244
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Forskningsöversikt (refereegranskat)abstract
- Electroweak measurements performed with data taken at the electron positron collider LEP at CERN from 1995 to 2000 are reported. The combined data set considered in this report corresponds to a total luminosity of about 3 fb(-1) collected by the four LEP experiments ALEPH, DELPHI, 13 and OPAL, at centre-of-mass energies ranging from 130 GeV to 209 GeV. Combining the published results of the four LEP experiments, the measurements include total and differential cross-sections in photon-pair, fermion-pair and four-fermion production, the latter resulting from both double-resonant WW and ZZ production as well as singly resonant production. Total and differential cross-sections are measured precisely, providing a stringent test of the Standard Model at centre-of-mass energies never explored before in electron positron collisions. Final-state interaction effects in four-fermion production, such as those arising from colour reconnection and Bose Einstein correlations between the two W decay systems arising in WW production, are searched for and upper limits on the strength of possible effects are obtained. The data are used to determine fundamental properties of the W boson and the electroweak theory. Among others, the mass and width of the W boson, m(w) and Gamma(w), the branching fraction of W decays to hadrons, B(W -> had), and the trilinear gauge-boson self-couplings g(1)(Z), K-gamma and lambda(gamma), are determined to be: m(w) = 80.376 +/- 0.033 GeV Gamma(w) = 2.195 +/- 0.083 GeV B(W -> had) = 67.41 +/- 0.27% g(1)(Z) = 0.984(-0.020)(+0.018) K-gamma - 0.982 +/- 0.042 lambda(gamma) = 0.022 +/- 0.019. (C) 2013 Elsevier B.V. All rights reserved.
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| 2. |
- Meech, K. J., et al.
(författare)
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EPOXI: Comet 103P/Hartley 2 Observations from a Worldwide Campaign
- 2011
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Ingår i: Astrophysical Journal Letters. - London : IOP. - 2041-8213 .- 2041-8205. ; 734:L1, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- Earth- and space-based observations provide synergistic information for space mission encounters by providing data over longer timescales, at different wavelengths and using techniques that are impossible with an in situ flyby. We report here such observations in support of the EPOXI spacecraft flyby of comet 103P/Hartley 2. The nucleus is small and dark, and exhibited a very rapidly changing rotation period. Prior to the onset of activity, the period was ~16.4?hr. Starting in 2010 August the period changed from 16.6?hr to near 19?hr in December. With respect to dust composition, most volatiles and carbon and nitrogen isotope ratios, the comet is similar to other Jupiter-family comets. What is unusual is the dominance of CO 2 -driven activity near perihelion, which likely persists out to aphelion. Near perihelion the comet nucleus was surrounded by a large halo of water-ice grains that contributed significantly to the total water production.
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| 3. |
- Klionsky, Daniel J., et al.
(författare)
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Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
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Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
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Forskningsöversikt (refereegranskat)abstract
- In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
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| 4. |
- Berk, J.L., et al.
(författare)
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The diflunisal trial : update on study drug tolerance and disease progression
- 2011
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Ingår i: Amyloid : the international journal of experimental and clinical investigation : the official journal of the International Society of Amyloidosis. - : Informa UK Limited. - 1744-2818. ; 18:Suppl. 1, s. 191-192
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Tidskriftsartikel (refereegranskat)abstract
- Abstract: Familial amyloidotic polyneuropathy (FAP) is a lethal genetic disorder that affects the peripheral and autonomic nervous systems, heart, gastro-intestinal (GI) tract, and soft tissues. Disease progression is increasingly reported following liver transplantation, the only proven treatment for FAP. Small molecule thyroxine mimetics stabilize transthyretin, inhibiting FAP amyloid fibril formation under stringent in vitro conditions. We report on the progress of an international, randomized placebo-controlled study designed to determine the effect of diflunisal, a thyroxine mimetic, on neurologic disease progression in patients with active FAP. Our experience to date indicates diflunisal is well tolerated by this study cohort and that neurologic disease advances more rapidly in FAP than it does in diabetes mellitus.Background: Transthyretin-related familial amyloidotic polyneuropathy (FAP) is a lethal autosomal dominant genetic disorder that predominantly affects the peripheral nervous system. FAP amyloid fibrils result from the misfolding of transthyretin, a transport protein predominantly produced by the liver. Although liver transplantation effectively treats patients with certain FAP mutations and limited disease, reports increasingly document progressive amyloid deposition following transplantation [1,2]. Alternative treatments are needed. In vitro investigations and a phase I clinical trial have demonstrated that thyroxine and small molecule mimetics, e.g. diflunisal, inhibit tetrameric transthyretin dissociation and suppress amyloid fibril formation [3,4].Methods: To examine the effect of diflunisal on disease progression in FAP, we designed a randomized, placebo controlled, double blind, multicenter international study employing the validated diabetic (DM) polyneuropathy metric, Neurologic Impairment Score + 7 attributes (NIS+7®), as the primary endpoint. A two-point change in NIS+7 correlates with clinically detectable progression of peripheral neuropathy among diabetics [5]. Entry criteria include proven FAP genotype, biopsy-proven amyloid deposits, and peripheral or autonomic neuropathy. Patients with alternate causes of neuropathy, other NSAID use, severe heart or kidney dysfunction, or previous liver transplantion are excluded. Study evaluations occur at entry, 6, 12, and 24 months. Adverse are collected by monthly telephone interviews, diary entries, and study site visit interactions. Relatedness of adverse events to study drug is assigned according to documentation in the investigational brochure, the protocol, the informed consent form; or at the investigator's discretion.Results: To date, 90 subjects have enrolled – 62 men and 28 women with median age 63 years (range 27–76 years). Adverse events tabulated by affected organ systems predominantly involved gastrointestinal events, more often attributed to disease complications than study drug side effects (Table 1). Although rare events, congestive heart failure in two subjects and GI bleeding in another prompted study drug discontinuation. Two disease-related deaths have occurred, both off study drug. Aggregate data from all study subjects (placebo and active drug arms) followed for at least 12 months identified a 3.2 point increase in median NIS+7 summated scores. In contrast, Dyck et al. [6] reported an annual 0.85 point increase in NIS+7 median scores in a large cohort of diabetics with polyneuropathy. Taken together, NIS+7 detected neurologic disease progression in this FAP cohort after 12 months observation. Additionally, NIS+7 measured disease advanced 3.5 times faster in our aggregate FAP study population than previously reported in DM.Conclusions: Diflunisal is well tolerated in FAP patients participating in the study. NIS+7, a composite scoring system, appears to be an effective study instrument for ATTR neuropathy, detecting significant change over 12 months observation. Neurologic disease progresses more rapidly in FAP than DM cohorts. The exact rate of disease progression in untreated FAP subjects detected by NIS+7 awaits unblinding of the data. These data will provide basis for future study design in FAP patients.
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| 5. |
- Kwok, Karen Y., et al.
(författare)
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Flux of Perfluorinated Chemicals through Wet Deposition in Japan, the United States, And Several Other Countries
- 2010
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 44:18, s. 7043-7049
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Tidskriftsartikel (refereegranskat)abstract
- The widespread distribution of perfluorinated chemicals (PFCs) in different environmental matrices has prompted concern about the sources, fate, and transport of these classes of chemicals. PFCs are present in the atmosphere, but only a few studies have investigated their occurrence in precipitation. In this study, concentrations of 20 PFCs, including C3-C5 short-chain PFCs, were quantified using HPLC-MS/MS in precipitation samples from Japan (n = 31), the United States (n = 12), China (n = 5), India (n = 2), and France (n = 2). Among the PFCs measured, perfluoropropanoic acid (PFPrA) was detected in all of the precipitation samples. Average total PFC concentrations ranged from 1.40 to 18.1 ng/L for the seven cities studied. The greatest total PFC concentrations were detected in Tsukuba, Japan, whereas the lowest concentrations were detected in Patna, India. PFPrA, perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) were found to be the dominant PFCs in Japanese and U.S. precipitation samples. No observable seasonal trend was found in precipitation samples from two locations in Japan. Annual fluxes of PFCs were estimated for Japan and the U.S. and the evidence for precipitation as an effective scavenger of PFCs in the atmosphere is reported.
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| 6. |
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| 7. |
- Taniyasu, Sachi, et al.
(författare)
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Inter-laboratory trials for analysis of perfluorooctanesulfonate and perfluorooctanoate in water samples : Performance and recommendations
- 2013
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Ingår i: Analytica Chimica Acta. - : Elsevier. - 0003-2670 .- 1873-4324. ; 770, s. 111-120
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Tidskriftsartikel (refereegranskat)abstract
- The ISO 25101 (International Organization for Standardization, Geneva) describes a new international standard method for the determination of perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) in unfiltered samples of drinking and surface waters. The method is based on the extraction of target analytes by solid phase extraction, solvent elution, and determination by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). For the determination of the performance of this method, more than 20 laboratories from 9 different countries participated in an inter-laboratory trial in 2006. In addition, inter-laboratory trials were conducted in 2008 and 2009 for the analysis of perfluoroalkylsubstances (PFASs), including PFOS and PFOA, in water samples by following the protocols of Japanese Industrial Standard (JIS). Overall, the repeatability coefficients of variation (i.e., within-laboratory precision) for PFOS and PFOA in all water samples were between 3 and 11%, showing a adequate precision of the ISO and JIS methods. The reproducibility coefficients of variation (i.e., between-laboratory precision) were found to vary within a range of 7-31% for surface water and 20-40% for wastewater. The recoveries of PFOS and PFOA, as a measure of accuracy, varied from 84 to 100% for surface water and from 84 to 100% for wastewater among the samples with acceptable criteria for internal standards recovery. The determined concentrations of PFASs in samples compared well with the " true" values. The results of the inter-laboratory trial confirmed that the analytical methods are robust and reliable and can be used as a standard method for the analysis of target compounds in water samples.
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| 8. |
- Ahrens, Lutz, et al.
(författare)
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Distribution of polyfluoroalkyl compounds in water, suspended particulate matter and sediment from Tokyo Bay, Japan
- 2010
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Ingår i: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 79:3, s. 266-272
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Tidskriftsartikel (refereegranskat)abstract
- This study examined the environmental behaviour and fate of polyfluoroalkyl compounds (PFCs) found in water, suspended particulate matter (SPM) and sediment. The sampling of the sediment was performed at two stations from Tokyo Bay, Japan, in 2008. In addition, a depth profile of seawater was collected at three water layers from both sampling stations. The ∑PFC concentrations ranged from 16.7 to 42.3 ng L-1 in the water column, from 6.4 to 15.1 ng g-1 dry weight (dw) in the SPM fraction and from 0.29 to 0.36 dw in surface sediment. The distribution of PFCs was found to depend on their physicochemical characteristics. While short-chain perfluoroalkyl carboxylic acids (PFCAs) (C < 7) were exclusively detected in the dissolved phase, longer-chain PFCAs (C ≥ 7), perfluoroalkyl sulfonates (PFSAs), ethylperfluorooctane sulfonamidoacetic acid (EtFOSAA), and perfluorooctane sulfonamide (PFOSA) appeared to bind more strongly to particles. Results showed that the sorption of PFCs on SPM increases by 0.52-0.75 log units for each additional CF2 moiety and that the sorption of PFSAs was 0.71-0.76 log units higher compared to the PFCA analogs. In addition, the sorption of PFCs was influenced by the organic carbon content. These data are essential for modelling the transport and environmental fate of PFCs.
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| 9. |
- Ahrens, Lutz, et al.
(författare)
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Partitioning of perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS) and perfluorooctane sulfonamide (PFOSA) between water and sediment
- 2011
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Ingår i: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 85:5, s. 731-737
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Tidskriftsartikel (refereegranskat)abstract
- Laboratory partitioning experiments were conducted to elucidate the sorption behaviour and partitioning of perfluoroalkyl compounds (PFCs). Three different sediment types were used and separately spiked with perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS) and perfluorooctane sulfonamide (PFOSA) at low environmentally realistic concentrations. PFOA, PFOS and PFOSA were mainly distributed in the dissolved phase at low suspended solid concentrations, indicating their long-range transport potential in the marine environment. In all cases, the equilibrium isotherms were linear and the organic carbon normalised partition coefficients (K OC) decreased in the following order: PFOSA (log K OC=4.1±0.35cm 3g -1)>PFOS (3.7±0.56cm 3g -1)>PFOA (2.4±0.12cm 3g -1). The level of organic content had a significant influence on the partitioning. For the sediment with negligible organic content the density of the sediment became the most important factor influencing the partitioning. Ultimately, data on the partitioning of PFCs between aqueous media and suspended solids are essential for modelling their transport and environmental fate.
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| 10. |
- Austin, John, et al.
(författare)
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Chemistry-climate model simulations of spring Antarctic ozone
- 2010
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Ingår i: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 115, s. D00M11-
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Tidskriftsartikel (refereegranskat)abstract
- Coupled chemistry-climate model simulations covering the recent past and continuing throughout the 21st century have been completed with a range of different models. Common forcings are used for the halogen amounts and greenhouse gas concentrations, as expected under the Montreal Protocol (with amendments) and Intergovernmental Panel on Climate Change A1b Scenario. The simulations of the Antarctic ozone hole are compared using commonly used diagnostics: the minimum ozone, the maximum area of ozone below 220 DU, and the ozone mass deficit below 220 DU. Despite the fact that the processes responsible for ozone depletion are reasonably well understood, a wide range of results is obtained. Comparisons with observations indicate that one of the reasons for the model underprediction in ozone hole area is the tendency for models to underpredict, by up to 35%, the area of low temperatures responsible for polar stratospheric cloud formation. Models also typically have species gradients that are too weak at the edge of the polar vortex, suggesting that there is too much mixing of air across the vortex edge. Other models show a high bias in total column ozone which restricts the size of the ozone hole (defined by a 220 DU threshold). The results of those models which agree best with observations are examined in more detail. For several models the ozone hole does not disappear this century but a small ozone hole of up to three million square kilometers continues to occur in most springs even after 2070.
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