1. |
- Gerkin, RC, et al.
(författare)
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The best COVID-19 predictor is recent smell loss: a cross-sectional study
- 2020
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Ingår i: medRxiv : the preprint server for health sciences. - : Cold Spring Harbor Laboratory.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- BackgroundCOVID-19 has heterogeneous manifestations, though one of the most common symptoms is a sudden loss of smell (anosmia or hyposmia). We investigated whether olfactory loss is a reliable predictor of COVID-19.MethodsThis preregistered, cross-sectional study used a crowdsourced questionnaire in 23 languages to assess symptoms in individuals self-reporting recent respiratory illness. We quantified changes in chemosensory abilities during the course of the respiratory illness using 0-100 visual analog scales (VAS) for participants reporting a positive (C19+; n=4148) or negative (C19-; n=546) COVID-19 laboratory test outcome. Logistic regression models identified singular and cumulative predictors of COVID-19 status and post-COVID-19 olfactory recovery.ResultsBoth C19+ and C19-groups exhibited smell loss, but it was significantly larger in C19+ participants (mean±SD, C19+: -82.5±27.2 points; C19-: -59.8±37.7). Smell loss during illness was the best predictor of COVID-19 in both single and cumulative feature models (ROC AUC=0.72), with additional features providing negligible model improvement. VAS ratings of smell loss were more predictive than binary chemosensory yes/no-questions or other cardinal symptoms, such as fever or cough. Olfactory recovery within 40 days was reported for ∼50% of participants and was best predicted by time since illness onset.ConclusionsAs smell loss is the best predictor of COVID-19, we developed the ODoR-19 tool, a 0-10 scale to screen for recent olfactory loss. Numeric ratings ≤2 indicate high odds of symptomatic COVID-19 (4<OR<10), which can be deployed when viral lab tests are impractical or unavailable.
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2. |
- Dent, W. R. F., et al.
(författare)
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GASPS-A Herschel Survey of Gas and Dust in Protoplanetary Disks: Summary and Initial Statistics
- 2013
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Ingår i: Publications of the Astronomical Society of the Pacific. - : IOP Publishing. - 0004-6280 .- 1538-3873. ; 125:927, s. 477-505
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Tidskriftsartikel (refereegranskat)abstract
- We describe a large-scale far-infrared line and continuum survey of protoplanetary disk through to young debris disk systems carried out using the ACS instrument on the Herschel Space Observatory. This Open Time Key program, known as GASPS (Gas Survey of Protoplanetary Systems), targeted similar to 250 young stars in narrow wavelength regions covering the [OI] fine structure line at 63 mu m the brightest far-infrared line in such objects. A subset of the brightest targets were also surveyed in [OI]145 mu m, [CII] at 157 mu m, as well as several transitions of H2O and high-excitation CO lines at selected wavelengths between 78 and 180 mu m. Additionally, GASPS included continuum photometry at 70, 100 and 160 mu m, around the peak of the dust emission. The targets were SED Class II-III T Tauri stars and debris disks from seven nearby young associations, along with a comparable sample of isolated Herbig AeBe stars. The aim was to study the global gas and dust content in a wide sample of circumstellar disks, combining the results with models in a systematic way. In this overview paper we review the scientific aims, target selection and observing strategy of the program. We summarise some of the initial results, showing line identifications, listing the detections, and giving a first statistical study of line detectability. The [OI] line at 63 mu m was the brightest line seen in almost all objects, by a factor of similar to 10. Overall [OI]63 mu m detection rates were 49%, with 100% of HAeBe stars and 43% of T Tauri stars detected. A comparison with published disk dust masses (derived mainly from sub-mm continuum, assuming standard values of the mm mass opacity) shows a dust mass threshold for [OI] 63 mu m detection of similar to 10(-5) M-circle dot. Normalising to a distance of 140 pc, 84% of objects with dust masses >= 10(-5) M-circle dot can be detected in this line in the present survey; 32% of those of mass 10(-6)-10(-5) M-circle dot, and only a very small number of unusual objects with lower masses can be detected. This is consistent with models with a moderate UV excess and disk flaring. For a given disk mass, [OI] detectability is lower for M stars compared with earlier spectral types. Both the continuum and line emission was, in most systems, spatially and spectrally unresolved and centred on the star, suggesting that emission in most cases was from the disk. Approximately 10 objects showed resolved emission, most likely from outflows. In the GASPS sample, [OI] detection rates in T Tauri associations in the 0.3-4 Myr age range were similar to 50%. For each association in the 5-20 Myr age range, similar to 2 stars remain detectable in [OI]63 mu m, and no systems were detected in associations with age >20 Myr. Comparing with the total number of young stars in each association, and assuming a ISM-like gas/dust ratio, this indicates that similar to 18% of stars retain a gas-rich disk of total mass similar to 1 M-Jupiter for 1-4 Myr, 1-7% keep such disks for 5-10 Myr, but none are detected beyond 10-20 Myr. The brightest [OI] objects from GASPS were also observed in [OI]145 mu m, [CII]157 mu m and CO J = 18 - 17, with detection rates of 20-40%. Detection of the [CII] line was not correlated with disk mass, suggesting it arises more commonly from a compact remnant envelope.
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3. |
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5. |
- Mathews, G. S., et al.
(författare)
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GAS in Protoplanetary Systems (GASPS) I. First results
- 2010
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 518:Article Number: L127
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Tidskriftsartikel (refereegranskat)abstract
- Context. Circumstellar discs are ubiquitous around young stars, but rapidly dissipate their gas and dust on timescales of a few Myr. The Herschel Space Observatory allows for the study of the warm disc atmosphere, using far-infrared spectroscopy to measure gas content and excitation conditions, and far-IR photometry to constrain the dust distribution. Aims. We aim to detect and characterize the gas content of circumstellar discs in four targets as part of the Herschel science demonstration phase. Methods. We carried out sensitive medium resolution spectroscopy and high sensitivity photometry at gimel similar to 60-190 mu m using the Photodetector Array Camera and Spectrometer instrument on the Herschel Space Observatory. Results. We detect [OI] 63 mu m emission from the young stars HD 169142, TW Hydrae, and RECX 15, but not HD 181327. No other lines, including [CII] 158 and [OI] 145, are significantly detected. All four stars are detected in photometry at 70 and 160 mu m. Extensive models are presented in associated papers.
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6. |
- Meeus, G., et al.
(författare)
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Gas in the protoplanetary disc of HD 169142: Herschel's view
- 2010
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 518:Article Number: L124
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Tidskriftsartikel (refereegranskat)abstract
- In an effort to simultaneously study the gas and dust components of the disc surrounding the young Herbig Ae star HD 169142, we present far-IR observations obtained with the PACS instrument onboard the Herschel Space Observatory. This work is part of the open time key program GASPS, which is aimed at studying the evolution of protoplanetary discs. To constrain the gas properties in the outer disc, we observed the star at several key gas-lines, including [OI] 63.2 and 145.5 mu m, [CII] 157.7 mu m, CO 72.8 and 90.2 mu m, and o-H2O 78.7 and 179.5 mu m. We only detect the [OI] 63.2 mu m line in our spectra, and derive upper limits for the other lines. We complement our data set with PACS photometry and (CO)-C-12/13 data obtained with the Submillimeter Array. Furthermore, we derive accurate stellar parameters from optical spectra and UV to mm photometry. We model the dust continuum with the 3D radiative transfer code MCFOST and use this model as an input to analyse the gas lines with the thermo-chemical code ProDIMo. Our dataset is consistent with a simple model in which the gas and dust are well-mixed in a disc with a continuous structure between 20 and 200 AU, but this is not a unique solution. Our modelling effort allows us to constrain the gas-to-dust mass ratio as well as the relative abundance of the PAHs in the disc by simultaneously fitting the lines of several species that originate in different regions. Our results are inconsistent with a gas-poor disc with a large UV excess; a gas mass of 5.0 +/- 2.0 x 10(-3) M-circle dot is still present in this disc, in agreement with earlier CO observations.
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8. |
- Oleszkiewicz, A., et al.
(författare)
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Hedonic perception of odors in children aged 5–8 years is similar across 18 countries : Preliminary data
- 2022
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Ingår i: International Journal of Pediatric Otorhinolaryngology. - : Elsevier BV. - 0165-5876 .- 1872-8464. ; 157
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Olfactory preference emerges very early in life, and the sense of smell in children rapidly develops until the second decade of life. It is still unclear whether hedonic perception of odors is shared in children inhabiting different regions of the globe.Methods: Five-hundred ten healthy children (N = 510; ngirls = 256; nboys = 254) aged from 5 to 8 years from 18 countries rated the pleasantness of 17 odors.Results: The hedonic perception of odors in children aged between 5 and 8 years was rather consistent across 18 countries and mainly driven by the qualities of an odor and the overall ability of children to label odorants.Conclusion: Conclusions from this study, being a secondary analysis, are limited to the presented set of odors that were initially selected for the development of U-Sniff test and present null findings for the cross-cultural variability in hedonic perception of odors across 18 countries. These two major issues should be addressed in the future to either contradict or replicate the results presented herewith. This research lays fundament for posing further research questions about the developmental aspects of hedonic perception of odors and opens a new door for investigating cross-cultural differences in chemosensory perception of children.
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10. |
- Pinte, C., et al.
(författare)
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The Herschel view of GAS in Protoplanetary Systems (GASPS) First comparisons with a large grid of models
- 2010
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 518:Article Number: L126
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Tidskriftsartikel (refereegranskat)abstract
- The Herschel GASPS key program is a survey of the gas phase of protoplanetary discs, targeting 240 objects which cover a large range of ages, spectral types, and disc properties. To interpret this large quantity of data and initiate self-consistent analyses of the gas and dust properties of protoplanetary discs, we have combined the capabilities of the radiative transfer code MCFOST with the gas thermal balance and chemistry code ProDiMo to compute a grid of approximate to 300 000 disc models (DENT). We present a comparison of the first Herschel/GASPS line and continuum data with the predictions from the DENT grid of models. Our objective is to test some of the main trends already identified in the DENT grid, as well as to define better empirical diagnostics to estimate the total gas mass of protoplanetary discs. Photospheric UV radiation appears to be the dominant gas-heating mechanism for Herbig stars, whereas UV excess and/or X-rays emission dominates for T Tauri stars. The DENT grid reveals the complexity in the analysis of far-IR lines and the difficulty to invert these observations into physical quantities. The combination of Herschel line observations with continuum data and/or with rotational lines in the (sub-)millimetre regime, in particular CO lines, is required for a detailed characterisation of the physical and chemical properties of circumstellar discs.
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11. |
- Thi, W. F., et al.
(författare)
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Herschel-PACS observation of the 10 Myr old T Tauri disk TW Hya Constraining the disk gas mass
- 2010
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 518:Article Number: L125
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Tidskriftsartikel (refereegranskat)abstract
- Planets are formed in disks around young stars. With an age of similar to 10 Myr, TW Hya is one of the nearest T Tauri stars that is still surrounded by a relatively massive disk. In addition a large number of molecules has been found in the TW Hya disk, making TW Hya the perfect test case in a large survey of disks with Herschel-PACS to directly study their gaseous component. We aim to constrain the gas and dust mass of the circumstellar disk around TW Hya. We observed the fine-structure lines of [OI] and [CII] as part of the open-time large program GASPS. We complement this with continuum data and ground-based (12) CO 3-2 and (CO)-C-13 3-2 observations. We simultaneously model the continuum and the line fluxes with the 3D Monte-Carlo code MCFOST and the thermo-chemical code ProDiMo to derive the gas and dust masses. We detect the [OI] line at 63 mu m. The other lines that were observed, [OI] at 145 mu m and [CII] at 157 mu m, are not detected. No extended emission has been found. Preliminary modeling of the photometric and line data assuming [(CO)-C-12]/[(CO)-C-13] = 69 suggests a dust mass for grains with radius
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13. |
- Sandell, Rolf, et al.
(författare)
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As time goes by. Long-term outcomes of psychoanalysis and long-term psychotherapy
- 1999
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Ingår i: Forum der Psychoanalyse (Print). - 0178-7667 .- 1437-0751. ; 15:4, s. 327-347
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Tidskriftsartikel (refereegranskat)abstract
- Generalizations about the outcomes of psychotherapy are essentially based on research on brief therapies with quite short follow-up. The present paper is a survey of some of the findings in an effectiveness study of psychoanalysis and long-term psychotherapy, typically psychoanalytically oriented, in private practice. The design was a three-wave panel comprising more than 700 patients. At the end of the third wave, 418 patients in different phases of treatment remained in the sample. Across a reconstructed time scale covering roughly seven years, before, during, and after treatment, the 74 psychoanalysis cases described a very positive development, whereas the development among the 331 psychotherapy cases was moderately positive. The findings emphasize the importance of extended follow-up. When therapist variables are considered, therapeutic experience had complex or mixed associations with patients outcome. Especially positive were high age and many years, in private practice, after licensing. Therapeutic ideals and attitudes divided the therapist group in three subgroups, one of which was characterized by purely classical psychoanalytic views on the values of support, friendliness etc. Therapists in the classically psychoanalytic cluster were found to do poorly with patients in psychotherapy, in contrast to patients in psychoanalysis. It is concluded that psychoanalysis and psychodynamically oriented psychotherapy are qualitatively different.
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15. |
- Sandell, Rolf, et al.
(författare)
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Differences in long-term effects of psychoanalysis and extended psychotherapy. Findings from the stockholm psychoanalysis and psychotherapy project.
- 2001
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Ingår i: Psyche. - 0033-2623. ; 55:3, s. 277-310
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Tidskriftsartikel (refereegranskat)abstract
- The authors present the major findings of a targe-scale study on subsidized psychoanalyses and long-term psychotherapies in Sweden. Over 400 persons examined at various stages of treatment were re-examined in a follow-up study three years later using face-to-face interviews, questionnaires and official statistics. The significant outcomes from the evaluation of the data are a) the significantly better treatment results achieved by psychoanalysis compared with psychotherapy, b) the better results achieved by more experienced psychoanalysts, c) the higher success rate achieved by female treatment-providers, d) the positive effect of high treatment duration and high session frequency on the treatment and e) the negative effect of the psychoanalytic stance into psychotherapeutic setting.
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16. |
- Sandell, Rolf, et al.
(författare)
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Therapist attitudes and patient outcomes : II. Therapist attitudes influence change during treatment
- 2007
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Ingår i: Psychotherapy Research. - : Informa UK Limited. - 1050-3307 .- 1468-4381. ; 17:2, s. 201-211
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Tidskriftsartikel (refereegranskat)abstract
- Psychotherapists' beliefs and attitudes in therapeutic matters, according to the Therapist Attitudes Scales (TASC-2) (Sandell et al., 2004), were related to symptom distress, as measured by the Symptom Checklist-90, in 2 groups of patients: one in ongoing psychoanalytical psychotherapy and the other posttreatment. In the posttreatment group, the zero-order correlations with symptom distress were significant for the therapist's attitudes toward kindness and insight as curative factors and supportiveness as a therapeutic style and his or her views on the nature of psychotherapy as a form of artistry, however, they were all near zero and nonsignificant in the in-treatment group. To account for correlations among the attitude variables, multiple regression analyses were compared between the groups. The multiple correlation was essentially zero in the latter group, whereas there was a significant multiple correlation of .51 in the former group. Thus Posttreatment outcome was significantly related to the therapist's position on the TASC-2 scales. Kindness and Artistry had particularly strong relations with the posttreatment results, with Neutrality acting like a suppressor. The pattern of relations suggested that therapist attitudes functioned as moderators rather than as mediators.
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17. |
- Sandell, Rolf, et al.
(författare)
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Therapist attitudes and patient outcomes : I. Development and validation of the therapeutic attitudes scales (TASC-2)
- 2004
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Ingår i: Psychotherapy Research. - : Informa UK Limited. - 1050-3307 .- 1468-4381. ; 14:4, s. 469-484
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Tidskriftsartikel (refereegranskat)abstract
- The aims of the study were to develop and standardize, using a random sample of licensed psychotherapists in Sweden, an instrument to explore therapeutic attitudes. Nine factors were extracted and cross-validated from Therapeutic Identity, a comprehensive questionnaire. The factor scales predicted with considerable accuracy self-designated theoretical orientations of the therapists and were associated with therapists' level of experience. A cluster analysis of the therapists on the basis of the factor scales revealed interesting variations, particularly within the psychodynamic and eclectic parts of the spectrum of therapeutic attitudes. © 2004 Society for Psychotherapy Research.
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18. |
- Sandell, Rolf, et al.
(författare)
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Therapist attitudes and patient outcomes. III. A latent class analysis of therapists
- 2006
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Ingår i: Psychology and Psychotherapy. - 1476-0835 .- 2044-8341. ; 79:4, s. 629-647
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Tidskriftsartikel (refereegranskat)abstract
- Background. Previous research has reported large differences in treatment results between individual therapists practising the same type of psychotherapy, but little is as yet known about the factors explaining this variation. In previous studies the authors have found associations with therapeutic attitudes as measured by the TASC 2 scales. Methods. A sample of 160 therapists were clustered in a non-parametric latent class (LC) regression modelling of their patients' repeated self-ratings on the SCL-90 across stages in psychotherapeutic treatment. This classification was then explored in relation to the therapists' TASC 2 scores. Results. Five classes were identified differing widely in terms of the patients' outcome trajectories. Membership in these classes was significantly influenced by the therapists' scores on the TASC 2 scales. The adjustment, neutrality and artistry scales of the TASC 2 were found specifically discriminative. A discriminant analysis confirmed the findings in general. Collectively, the TASC 2 scales were able to assign 56% of the therapists to their correct latent class, in comparison with 20% by chance. Conclusions. Therapists with a psychoanalytic or eclectic orientation are systematically different in terms of the outcomes they tend to contribute to with their patients. This variation is partly accounted for by differences in their therapeutic attitudes. © 2006 The British Psychological Society.
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19. |
- Sandell, Rolf, et al.
(författare)
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Therapists' therapies : The relation between training therapy and patient change in long-term psychotherapy and psychoanalysis
- 2006
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Ingår i: Psychotherapy Research. - : Informa UK Limited. - 1050-3307 .- 1468-4381. ; 16:3, s. 306-316
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Tidskriftsartikel (refereegranskat)abstract
- Patients' development across stages in long-term psychodynamic psychotherapy or psychoanalysis was studied in relation to various parameters of their therapists' training, or personal, therapies. The change variable was symptom distress, the General Symptom Index, according to the Symptom Checklist-90. A series of latent class regression analyses revealed that one class of therapists (16% of the sample) whose patients had the least change in treatment, and in fact had nonsignificant deterioration, was significantly overrepresented by psychotherapists with long psychoanalyses for their training therapies. Alternative interpretations of the findings are discussed. © 2006 Society for Psychotherapy Research.
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21. |
- Sandell, Rolf, et al.
(författare)
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Varieties of long-term outcome among patients in psychoanalysis and long-term psychotherapy - A review of findings in the Stockholm Outcome of Psychoanalysis and Psychotherapy Project (STOPPP)
- 2000
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Ingår i: International Journal of Psychoanalysis. - 0020-7578 .- 1745-8315. ; 81, s. 921-942
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports the main findings of a large-scale study of subsidised psychoanalysis and long-term psychotherapy. More than 400 people in various phases, before, during and after subsidised psychoanalysis or long-term psychodynamic psyche therapy, were followed up for a period of three years with personal interviews, questionnaires and official statistics. Our analyses revealed progressive improvement the longer patients were in treatment-impressively strong among patients in psychoanalysis-on self-rating measures of symptom distress and morale. Improvement, however was equally weak in both groups on a self-rating measure of social relations. Dosage factors (treatment duration and session frequency in combination) partly accounted for the outcome differences between those referred to psychoanalysis and those referred to long-term psychotherapy. Attitudes and ideals among therapists and analysts concerning the goals and means of psychotherapy were also associated with patient outcome, although in rather complex ways. A significant part of the outcome differences between patients in psychoanalysis and in psychotherapy could be explained by the adoption, in a large group of therapists, of orthodox psychoanalytic attitudes that seemed to be counterproductive in the practice of psychotherapy but not in psychoanalysis. It is suggested that this effect may be a negative transfer of the psychoanalytic stance into psychotherapeutic practice and that this may be especially pronounced when the attitudes are not backed tip by psychoanalytic training.
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22. |
- Sims, D. A., et al.
(författare)
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(γ,n) study of the isovector quadrupole resonance in 40Ca
- 1997
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Ingår i: Physical Review C: covering nuclear physics. - 2469-9985. ; 55:3, s. 1288-1294
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Tidskriftsartikel (refereegranskat)abstract
- The forward-to-backward asymmetry of neutrons emitted in the 40Ca(γ,n0) reaction was measured at photon energies in the range of 27–50 MeV. An energy-dependent asymmetry was observed that is interpreted as evidence of interference between the isovector quadrupole resonance and the giant dipole resonance. Data analysis in terms of semiclassical and direct-semidirect models estimate the isovector quadrupole resonance to be at an excitation energy of 31.0±1.5 MeV, with a width of 16.0±1.5 MeV, and exhausting most of the energy-weighted sum rule for the isovector quadrupole resonance.
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29. |
- Sandell, A., et al.
(författare)
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Observation of a low-energy adsorbate core-level satellite for CO bonded to palladium : Coordination-dependent effects
- 1998
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Ingår i: Physical Review B (Condensed Matter). - 0163-1829. ; 57:20, s. 13199-13208
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Tidskriftsartikel (refereegranskat)abstract
- A strong low-energy shake-up satellite for CO adsorbed on Pd is observed. The occurrence of the satellite is established for the CO/1 ML Pd/Mo(110) system at a coverage where CO adsorbs exclusively on-top. Comparisons with CO adsorbed on Pd single-crystal surfaces and small supported Pd particles indicate that the strongly increased satellite intensity is due to the decreased CO-Pd interaction strength for on-top adsorbed CO. This can be used to get further insight into the structure and bonding properties of the adsorbate system. Since a low-energy shake-up feature may be misinterpreted as a chemically shifted component, the conclusion is that great care has to be taken in the evaluation of adsorbate core-level spectra for systems with large variations in adsorption strength depending on the adsorbate sites. Large variations in the CO site distribution may furthermore occur depending on the nature of the Pd substrate: Adsorption of CO on 1 ML Pd/Mo(110) leads to an overlayer dominated by an on-top species and, likewise, the CO overlayer formed on small Pd particles after large doses has a large fraction of on-top bonded species. This is in strong contrast to Pd single-crystal surfaces, where CO adsorbed in more highly coordinated sites is abundant.
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32. |
- Adler, Jan-Olof, et al.
(författare)
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The upgraded photon tagging facility at the MAX IV Laboratory
- 2013
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 715, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- A description is given of the upgraded photon tagging facility at the MAX IV Laboratory. Two magnetic spectrometers are used to momentum analyze post-bremsstrahlung electrons. The tagged photon range extends from 10 to 180 MeV with an energy resolution of about 300 keV. The system has been operated at rates up to 4 x 10(6) photons s(-1) MeV (-1). Different diagnostic tools are described as well as the experimental program.
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33. |
- Alfredsson, Ylfi, et al.
(författare)
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Phase and molecular orientation in H2Pc on conducting glass : characterization of two deposition methods
- 2005
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Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 493:1-2, s. 13-19
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Tidskriftsartikel (refereegranskat)abstract
- In this study, metal-free phthalocyanine has been deposited on a conducting glass surface by two methods: by spreading the molecular powder directly on the substrate in air and by vapor sublimation under ultra-high vacuum conditions (evaporation). The films have been characterized by means of core level X-ray Photoemission Spectroscopy, X-ray Absorption Spectroscopy (XAS) and Ultra Violet and Visible absorption spectroscopy (UV-Vis). Our results show that the two deposition methods produce molecular overlayers in different polymorphic phases; the UV-Vis measurements indicate that the film obtained by powder deposition is of x-phase type whereas sublimation leads to an α-polymorph structure. The XAS results show that in the powder deposited film the molecules are mainly oriented parallel to the surface. This is opposite to the case of the vapor deposited film, where the molecules mainly are oriented orthogonal to the surface.
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34. |
- Alfredsson, Y, et al.
(författare)
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Phase and molecular orientation in metal-free phthalocyanine films on conducting glass: Characterization of two deposition methods
- 2005
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Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090. ; 493:1-2, s. 13-19
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Tidskriftsartikel (refereegranskat)abstract
- in this study, metal-free phthalocyanine has been deposited on a conducting glass surface by two methods: by spreading the molecular powder directly on the substrate in air and by vapor sublimation under ultra-high vacuum conditions (evaporation). The films have been characterized by means of core level X-ray Photoemission Spectroscopy, X-ray Absorption Spectroscopy (XAS) and Ultra Violet and Visible absorption spectroscopy (UV-Vis). Our results show that the two deposition methods produce molecular overlayers in different polymorphic phases; the UV-Vis measurements indicate that the film obtained by powder deposition is of x-phase type whereas sublimation leads to an a-polymorph structure. The XAS results show that in the powder deposited film the molecules are mainly oriented parallel to the surface. This is opposite to the case of the vapor deposited film, where the molecules mainly are oriented orthogonal to the surface.
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35. |
- Beutler, A., et al.
(författare)
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Adsorption properties of a mixed surface studied by high resolution core level photoemission : CO/0.5 ML Pd/Rh(111)
- 1998
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Ingår i: Surface Science. - 0039-6028. ; 411:1-2, s. 111-122
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Tidskriftsartikel (refereegranskat)abstract
- The coverage-dependent adsorption properties of a laterally heterogeneous bimetallic surface have been investigated by high resolution core level photoemission and low energy electron diffraction. The specific system under study was CO adsorbed on a Rh(111) surface onto which 2D Pd islands (coverage 0.5 ML) were formed by vapor deposition. The CO adsorption properties of the heterogeneous surface were compared with CO adsorption on a Rh(111) surface covered with a full Pd monolayer and with previous results for the CO/Rh(111) system. For low exposures CO is only found on the Rh(111) patches which can be explained by diffusion of CO from the Pd islands onto Rh parts in the adsorption process. At higher exposures CO diffusion from Rh to Pd is indicated. The origin of the diffusion processes can be found in the different coverage-dependent CO adsorption energies on the two surface parts.
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36. |
- Beutler, A., et al.
(författare)
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Identification of a laterally mobile state during CO adsorption
- 2000
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Ingår i: Journal of Physics: Condensed Matter. - : IOP Publishing. - 0953-8984 .- 1361-648X. ; 12:6, s. 765-772
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated CO adsorption at 300 K on ∼ 1.5 atomic layer thick Pd films on a Mo(110) surface by high-resolution core level photoemission. We describe how high-resolution core level spectroscopy may be utilized to study the influence of laterally mobile states on the sticking probability of molecules on such a laterally heterogeneous surface. The present Pd films are laterally heterogeneous in the sense that the additional ∼ 0.5 atomic Pd layer forms mesoscopic one-layer thick islands on top of the first Pd layer. At 300 K, CO chemisorbs on these two-layer thick islands but not on the one-layer parts of the film. The rate at which these two-layer islands are filled by CO molecules as the surface is exposed to CO is found to be consistent with a picture where CO molecules that initially impinge on the one-layer parts of the surface enter a laterally mobile state and diffuse to the two-layer islands and adsorb there. This mobile state is in many respects similar to a classical precursor state.
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37. |
- Beutler, A., et al.
(författare)
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The influence of preadsorbed oxygen on the adsorption of CO on two-dimensional Pd islands on a Rh (111) surface
- 1998
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Ingår i: Surface Science. - 0039-6028. ; 418:2, s. 457-465
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Tidskriftsartikel (refereegranskat)abstract
- The influence of preadsorbed oxygen on the CO adsorption properties of a laterally heterogeneous bimetallic surface consisting of Pd islands on Rh(111) at a Pd coverage of 0.5 monolayers has been studied by high resolution core level photoemission. A surface consisting of clean Pd islands surrounded by oxygen-covered Rh(111) patches was prepared by predosing oxygen at room temperature. By applying core level photoemission to the Pd 3d5/2 and the C 1s levels, the adsorption of CO on this surface was studied with particular attention being paid to possible CO diffusion between the two surface parts. The CO molecules are found to diffuse from the oxygen-covered Rh(111) patches onto the Pd islands for low to medium CO exposures. This diffusion direction is opposite of that found previously for the 0.5 ML Pd on Rh(111) system with no oxygen predosing. This reversal of the diffusion direction is argued to be due to a large reduction of the CO adsorption energy on the Rh patches of the surface caused by the preadsorbed oxygen.
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- Chireh, A., et al.
(författare)
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Safety evaluation of high-risk myocardial micro-biopsy in a swine model
- 2022
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Ingår i: Heart and Vessels. - : Springer Nature. - 0910-8327 .- 1615-2573. ; 37:4, s. 697-704
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Tidskriftsartikel (refereegranskat)abstract
- The objective of the study was to investigate the safety profile of high-risk micro-endomyocardial biopsy (micro-EMB) compared to conventional EMB in a large animal model. Twenty pigs were subjected to a maximum of 30 consecutive biopsies, including sampling from the free ventricular wall, with either micro-EMB (n = 10) or conventional EMB (n = 10). There were no major complications in the micro-EMB group (0/10), compared to six major complications in the EMB group (6/10; p = 0.003). Survival analysis further highlighted these differences (p = 0.004). There were significantly higher volumes of pericardial effusion in the EMB group (p = 0.01). The study shows a safety advantage of micro-EMB compared to standard EMB in the experimental high-risk circumstances investigated in this animal study. These results indicate enhanced possibilities to collect samples from sensitive areas by using the micro-EMB technique instead of standard EMB.
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- Jacobse, Peter H., et al.
(författare)
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One Precursor but Two Types of Graphene Nanoribbons : On-Surface Transformations of 10,10'-Dichloro-9,9'-bianthryl on Ag(111)
- 2019
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 123:14, s. 8892-8901
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Tidskriftsartikel (refereegranskat)abstract
- On-surface synthesis has emerged in the last decade as a method to create graphene nanoribbons (GNRs) with atomic precision. The underlying premise of this bottom-up strategy is that precursor molecules undergo a well-defined sequence of inter- and intramolecular reactions, leading to the formation of a single product. As such, the structure of the GNR is encoded in the precursors. However, recent examples have shown that not only the molecule, but also the coinage metal surface on which the reaction takes place, plays a decisive role in dictating the nanoribbon structure. In this work, we use scanning probe microscopy and X-ray photoelectron spectroscopy to investigate the behavior of 10,10'-dichloro-9,9'-bianthryl (DCBA) on Ag(111). Our study shows that Ag(111) can induce the formation of both seven-atom wide armchair GNRs (7-acGNRs) and 3,1-chiral GNRs (3,1-cGNRs), demonstrating that a single molecule on a single surface can react to different nanoribbon products. We additionally show that coadsorbed dibromoperylene can promote surface-assisted dehydrogenative coupling in DCBA, leading to the exclusive formation of 3,1-cGNRs.
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