237 research outputs found
Resummation of infrared divergencies in the theory of atomic Bose gases
We present a general strong-coupling approach for the description of an
atomic Bose gas beyond the Bogoliubov approximation, when infrared divergences
start to occur that need to be resummed exactly. We consider the determination
of several important physical properties of the Bose gas, namely the chemical
potential, the contact, the speed of sound, the condensate density, the
effective interatomic interaction and the three-body recombination rate. It is
shown how the approach can be systematically improved with
renormalization-group methods and how it reduces to the Bogoliubov theory in
the weak-coupling limit
Cooling curves for neutron stars with hadronic matter and quark matter
The thermal evolution of isothermal neutron stars is studied with matter both
in the hadronic phase as well as in the mixed phase of hadronic matter and
strange quark matter. In our models, the dominant early-stage cooling process
is neutrino emission via the direct Urca process. As a consequence, the cooling
curves fall too fast compared to observations. However, when superfluidity is
included, the cooling of the neutron stars is significantly slowed down.
Furthermore, we find that the cooling curves are not very sensitive to the
precise details of the mixing between the hadronic phase and the quark phase
and also of the pairing that leads to superfluidity.Comment: 19 pages, 25 figure
The use of standard calendar software by individuals with acquired brain injury and cognitive complaints: a mixed methods study
PURPOSE: To explore the actual use of standard calendar software by people with acquired brain injury (ABI) and healthy individuals. METHOD: Mixed methods design with qualitative and quantitative analyses of the respondents' use of calendar software. Fifteen individuals with ABI and 15 healthy participants were enrolled. Participants were asked to execute five consecutive tasks using standard calendar software, which resembled everyday use of an electronic calendar. RESULTS: The core processes "task execution" and "information processing" were influenced by internal factors (cognitive and emotional processes and fatigue) as well as environmental factors (software features and distractions). Results obtained by qualitative and quantitative methods showed similar reaction patterns in both groups. However, ABI patients had more cognitive problems and showed stronger emotions during task performance than healthy participants. Healthy participants were more successful and needed less time and mental effort to perform a task. CONCLUSIONS: Although ABI patients were able to use standard calendar software, they became upset more easily, needed more effort, became tired sooner and more suddenly. Strategies to support ABI patients in the use of calendar software are suggested from multi-disciplinary perspectives
Augmented cognitive behavioral therapy for post stroke depressive symptoms:a randomized controlled trial
Item does not contain fulltextOBJECTIVE: To evaluate the effectiveness of individually tailored cognitive behavioral therapy (CBT) for reducing depressive symptoms with or without anxiety poststroke. DESIGN: Multicenter, assessor-blinded, randomized controlled trial. SETTING: Ambulatory rehabilitation setting. PARTICIPANTS: Patients who had a Hospital Anxiety and Depression Scale-depression subscale (HADS-D) score >7 at least 3 months poststroke (N=61). INTERVENTIONS: Participants were randomly allocated to either augmented CBT or computerized cognitive training (CCT). The CBT intervention was based on the principles of recognizing, registering, and altering negative thoughts and cognitions. CBT was augmented with goal-directed real-life activity training given by an occupational or movement therapist. MAIN OUTCOME MEASURES: HADS-D was the primary outcome, and measures of participation and quality of life were secondary outcomes. Outcome measurements were performed at baseline, immediately posttreatment, and at 4- and 8-month follow-up. Analysis was performed with linear mixed models using group (CBT vs CCT) as the between-subjects factor and time (4 assessments) as the within-subjects factor. RESULTS: Mixed model analyses showed a significant and persistent time effect for HADS-D (mean difference, -4.6; 95% confidence interval, -5.7 to -3.6; P<.001) and for participation and quality of life in both groups. There was no significant group x time effect for any of the outcome measures. CONCLUSIONS: Our augmented CBT intervention was not superior to CCT for the treatment of mood disorders after stroke. Future studies should determine whether both interventions are better than natural history.8 p
Dealing with a life changing event:The influence of spirituality and coping style on quality of life after survival of a cardiac arrest or myocardial infarction
Resting state EEG relates to short- and long-term cognitive functioning after cardiac arrest
Background: Approximately half of cardiac arrest survivors have persistent cognitive impairment. Guidelines recommend early screening to identify patients at risk for cognitive impairment, but there is no consensus on the best screening method. We aimed to identify quantitative EEG measures relating with short- and long-term cognitive function after cardiac arrest for potential to cognitive outcome prediction. Methods: We analyzed data from a prospective longitudinal multicenter cohort study designed to develop a prediction model for cognitive outcome after cardiac arrest. For the current analysis, we used twenty-minute EEG registrations from 80 patients around one week after cardiac arrest. We calculated power spectral density, normalized alpha-to-theta ratio (nATR), peak frequency, and center of gravity (CoG) of this peak frequency. We related these with global cognitive functioning (scores on the Montreal Cognitive Assessment (MoCA)) at one week, three and twelve months follow-up with multivariate mixed effect models, and with performance on standard neuropsychological examination at twelve months using Pearson correlation coefficients. Results: Each individual EEG parameter related to MoCA at one week (βnATR = 7.36; P < 0.01; βpeak frequency = 1.73, P < 0.01; βCoG = -9.88, P < 0.01). The nATR also related with the MoCA at three months ((βnATR = 2.49; P 0.01). No EEG metrics significantly related to the MoCA score at twelve months. nATR and peak frequency related with memory performance at twelve months. Results were consistent in sensitivity analyses. Conclusion: Early resting-state EEG parameters relate with short-term global cognitive functioning and with memory function at one year after cardiac arrest. Additional predictive values in multimodal prediction models need further study.</p
Chorioamnionitis induces hepatic inflammation and time-dependent changes of the enterohepatic circulation in the ovine fetus
Chorioamnionitis, inflammation of fetal membranes, is an important cause of preterm birth and a risk factor for the development of adverse neonatal outcomes including sepsis and intestinal pathologies. Intestinal bile acids (BAs) accumulation and hepatic cytokine production are involved in adverse intestinal outcomes. These findings triggered us to study the liver and enterohepatic circulation (EHC) following intra-amniotic (IA) lipopolysaccharide (LPS) exposure. An ovine chorioamnionitis model was used in which circulatory cytokines and outcomes of the liver and EHC of preterm lambs were longitudinally assessed following IA administration of 10 mg LPS at 5, 12 or 24h or 2, 4, 8 or 15d before preterm birth. Hepatic inflammation was observed, characterized by increased hepatic cytokine mRNA levels (5h – 2d post IA LPS exposure) and increased erythropoietic clusters (at 8 and 15 days post IA LPS exposure). Besides, 12h after IA LPS exposure, plasma BA levels were increased, whereas gene expression levels of several hepatic BA transporters were decreased. Initial EHC alterations normalized over time. Concluding, IA LPS exposure induces significant time-dependent changes in the fetal liver and EHC. These chorioamnionitis induced changes have potential postnatal consequences and the duration of IA LPS exposure might be essential herein
Cognition, emotional state, and quality of life of survivors after cardiac arrest with rhythmic and periodic EEG patterns
Aim: Rhythmic and periodic patterns (RPPs) on the electroencephalogram (EEG) in comatose patients after cardiac arrest have been associated with high case fatality rates. A good neurological outcome according to the Cerebral Performance Categories (CPC) has been reported in up to 10% of cases. Data on cognitive, emotional, and quality of life outcomes are lacking. We aimed to provide insight into these outcomes at one-year follow-up. Methods: We assessed outcome of surviving comatose patients after cardiac arrest with RPPs included in the ‘treatment of electroencephalographic status epilepticus after cardiopulmonary resuscitation’ (TELSTAR) trial at one-year follow-up, including the CPC for functional neurological outcome, a cognitive assessment, the hospital anxiety and depression scale (HADS) for emotional outcomes, and the 36-item short-form health survey (SF-36) for quality of life. Cognitive impairment was defined as a score of more than 1.5 SD below the mean on = 2 (sub)tests within a cognitive domain. Results: Fourteen patients were included (median age 58 years, 21% female), of whom 13 had a cognitive impairment. Eleven of 14 were impaired in memory, 9/14 in executive functioning, and 7/14 in attention. The median scores on the HADS and SF-36 were all worse than expected. Based on the CPC alone, 8/14 had a good outcome (CPC 1–2). Conclusion: Nearly all cardiac arrest survivors with RPPs during the comatose state have cognitive impairments at one-year follow-up. The incidence of anxiety and depression symptoms seem relatively high and quality of life relatively poor, despite ‘good’ outcomes according to the CPC
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