Electron transport measurements in liquid xenon with Xenoscope, a large-scale DARWIN demonstrator

The DARWIN observatory is a proposed next-generation experiment with 40 tonnes of liquid xenon as an active target in a time projection chamber. To study challenges related to the construction and operation of a multi-tonne scale detector, we have designed and constructed a vertical, full-scale demonstrator for the DARWIN experiment at the University of Zurich. Here, we present the first results from a several-months run with 343 kg of xenon and electron drift lifetime and transport measurements with a 53 cm tall purity monitor immersed in the cryogenic liquid. After 88 days of continuous purification, the electron lifetime reached a value of ( 664 ± 23 ) μ s . We measured the drift velocity of electrons for electric fields in the range (25-75) V/cm, and found values consistent with previous measurements. We also calculated the longitudinal diffusion constant of the electron cloud in the same field range, and compared with previous data, as well as with predictions from an empirical model.

The first dual-phase xenon TPC equipped with silicon photomultipliers and characterisation with 37 Ar

For the first time, a small dual-phase (liquid/gas) xenon time projection chamber was equipped with a top array of silicon photomultipliers for light and charge readout. Here we describe the instrument in detail, as well as the data processing and the event position reconstruction algorithms. We obtain a spatial resolution of ∼ 1.5 mm in the horizontal plane. To characterise the detector performance, we show calibration data with internal 83 m Kr and 37 Ar sources, and we detail the production of the latter as well as its introduction into the system. We finally compare the observed light and charge yields down to electronic recoil energies of 2.82 keV to predictions based on NEST v2.0.

[Treatment of fibromyalgia syndrome with gamma-hydroxybutyrate : A randomized controlled study]

BACKGROUND

The etiology of fibromyalgia syndrome is not yet fully understood. Current hypotheses suggest a potential role of gamma-hydroxybutyrate (GHB) in influencing endocrinological abnormalities in patients with fibromyalgia.

OBJECTIVE

The aim of the study was to investigate whether low dose GHB as a growth-hormone releasing substance reduces pain intensity and improves depressive mood, physical impairment and sleep quality in outpatients with fibromyalgia. Additionally, adverse events were recorded.

MATERIAL AND METHODS

The pilot study was conducted in the outpatient clinic for pain at the clinic for anesthesiology and surgical intensive care of the Charité Universitätsmedizin Berlin. In the study 25 female patients with fibromyalgia according to the criteria of the American College of Rheumatology were randomized into 2 groups. Over 15 weeks patients of the intervention group received 25 mg/kg body weight oral GHB before going to bed and were compared with a placebo control group. In addition, all patients participated in operant behavioral pain treatment in a group setting. Dependent variables were pain intensity, depressive mood, physical impairment and quality of sleep.

RESULTS

There were no group differences in the course of pain intensity (p = 0.61), depressive mood (p = 0.16), physical impairment (p = 0.25) and quality of sleep (p = 0.44); however, all symptoms improved across the groups from pretherapy to posttherapy. Low dose GHB did not increase growth hormone blood concentrations. The number of adverse events that were reported more than two times was similar in both groups.

DISCUSSION

Administration of low dose GHB did not yield clinical improvements in female outpatients with fibromyalgia. General improvement in the course of treatment may have resulted from operant behavioral pain therapy. Future studies on GHB should control hypothetical risk factors for identification of non-responders.

Cognitive-behavioral and operant-behavioral therapy for people with fibromyalgia

The current article reviews the cognitive-behavioral (CB) and operant-behavioral perspectives on chronic pain and suggests an answer to the question why changes in behaviors, attitudes, and emotions are associated with decreases in pain severity and impact discussing potential psychobiological mechanisms that may underlie cognitive and behavioral techniques. The impact of learning such as classical and operant conditioning in behaviors and physical responses including baroreflex sensitivity (BRS), as well as the influence of cognitions on pain perception and impact will be presented to explain general efficacy of cognitive-behavior therapy (CBT) and operant-behavioral therapy (OBT) in the treatment of people with fibromyalgia (FM) describing some of the limitations of published outcome studies. We discuss advances in moderation and mediation of treatment outcomes. Lastly, we will discuss the need for research that takes into account evidence-based medicine, methods that address treatment responders and non-responders, individual trajectories, how we might advance and refine CBT and OBT, and strategies related to relapse prevention, maintenance, and adherence-enhancement taking advantage of evolving, technological methods of service delivery. We provide recommendations of how to move forward in approaching studies of CBT and OBT efficacy as a function of better understanding of patient characteristics and contextual factors. We advocate for the potential of the CB perspective and principle of learning for all health care providers regardless of discipline or training and will give examples for making more effective the patient-rheumatologist-relationship by using the principles discussed.

Cognitive-behavioral mechanisms in a pain-avoidance and a pain-persistence treatment for high-risk fibromyalgia patients

OBJECTIVE

The heterogeneity of cognitive-behavioral patterns in patients with fibromyalgia (FM) has been proposed to underlie the variability in treatment outcomes. It has previously been shown that pain-avoidance and pain-persistence treatments tailored to the patient's pattern are effective in improving physical and psychological functioning and overall impact in high-risk patients with heightened psychological distress. In the present study, the cognitive-behavioral effects of these treatments were evaluated to provide insight into the main proposed mechanisms, specifically pain-avoidance behaviors and activity pacing in the pain-avoidance and pain-persistence treatments, respectively.

METHODS

High-risk FM patients were classified into 2 groups, pain avoidance and pain persistence, and randomized in groups to the relevant treatment or waiting-list control condition. The pain-avoidance and pain-persistence treatments both comprised 16 twice-weekly sessions of cognitive-behavioral therapy and exercise training. Cognitive--behavioral factors assessed at pre- and posttreatment and 6 months of followup were evaluated using linear mixed models.

RESULTS

A significant treatment effect was found for pain-avoidance behavior in the pain-avoidance treatment and for activity pacing in the pain-persistence treatment, showing improvements in the treatment condition relative to the controls. Furthermore, the effect on functioning was mediated by changes in pain-avoidance behavior in the pain-avoidance treatment and by changes in activity pacing in the pain-persistence treatment. Both treatments also showed significant improvements in other relevant cognitive-behavioral factors.

CONCLUSION

Both the pain-avoidance and pain-persistence treatments are effective in improving cognitive-behavioral factors in high-risk FM patients. Pain-avoidance behavior and activity pacing might be important mediating mechanisms for beneficial outcomes in pain-avoidance and pain-persistence treatments, respectively.

The influence of the 5‐HT3receptor antagonist tropisetron on pain in fibromyalgia: a functional magnetic resonance imaging pilot study

OBJECTIVE

Central pain processing is altered in patients with fibromyalgia syndrome (FMS). The serotonin metabolism, especially the 5-HT3 receptor, seems to play an important role.

METHODS

We investigated the effect of the local injection of the 5-HT3 receptor antagonist tropisetron on the perception and central processing of pain in FMS patients using painful mechanical stimulation and functional magnetic resonance imaging (fMRI) within the framework of a pre-/posttreatment double-blind design.

RESULTS

In the contralateral primary somatosensory cortex, contralateral posterior insula, and anterior cingulate cortex, we found that the activation was significantly reduced after treatment. On average, patients rated the stimulation-induced pain intensity as stronger in the session after treatment compared to before treatment, although the individual data revealed a heterogeneous pattern. All patients showed sensitisation during the painful stimulation, which was not influenced by the treatment.

CONCLUSIONS

Both the sensory-discriminative and motivational-affective components of pain as measured by fMRI were altered by tropisetron.

Comparison for quality assurance of 99mTc activity measurements with radionuclide calibrators

In 2005, the Physikalisch-Technische Bundesanstalt (PTB) and the QSA Global GmbH (QSA) organised a national comparison of (99m)Tc solution measurements. The purpose of this comparison was to gain information on the quality of routine activity measurements carried out in the field of nuclear medicine in Germany. In addition to this, an ampoule containing a calibrated (99m)Tc solution was sent from PTB to the Bureau International des Poids et Mesures (BIPM) to have the activity result entered into the database of the International Reference System (SIR), and thus demonstrating traceability of the measurements to the SI. In the following, we will report on the activity standardisation carried out at the PTB, and on the way in which the national comparison had been organised, and we will provide information on the analysis as well as on its results.

Neuroendokrine Ver�nderungen und Maladaptationen bei Fibromyalgie

This contribution presents the psychosocial, psychopathological, psycho- and elektrophysiological as well as endocrine results in the aetiopathogenesis of fibromyalgia syndrome (FMS). Three subgroups could be differentiated based on psychosocial learning processes. They differ in pain intensity and interference, affective distress, activity and spouse responses. They influence pain behavior and CNS activity in the sense of operant conditioning. The relationship between dysregulated pain modulation in the CNS and endocrine dysregulation of the HPA-axis, which seems to be relevant for the autonome hyporeaction of muscle and blood pressure, are discussed. The "dynamic processing model for FMS" is presented.

Differences in the autonomic reactivity pattern to psychological load in patients with hypertension and rheumatic diseases

As a ground-based reference study to a space experiment, a complex psychophysiological test battery (heart rate, blood pressure, skin conductance, finger temperature, forearm electromyogram during psychological loading task solving) was developed and first applied on two cohorts of subjects with different blood pressure levels at rest (53 hypertensive patients, and 30 normal controls). The data describing autonomic reactivity could be differentiated by cluster analysis into four Autonomic Outlet Types (AOT). The method was subsequently applied to 20 patients with systemic Lupus erythematosus and 13 subjects with rheumatoid arthritis to work out a discriminant function for classifying and testing it's validity. The AOT classification of all subjects showed a significant correlation with the different types of diseases.

On the determination of activity profiles in wide-area reference sources

A method is described for determining the depth distribution of the radioactive substance of alpha-emitting nuclides in a wide-area reference source. The method combines measurements and calculations. In the experimental part, the energy spectrum of the source is measured by means of an alpha spectrometer. The energy spectrum is then modelled by the Monte Carlo method, taking into account energy loss of alpha particles in the source matrix, energy-loss straggling and the parameters of the spectrometer. Additional parameters for the characterization of reference sources are derived from the integral of the depth distribution. The investigations prove that the production process of commercial sources can be controlled in such a way that more than 90% of the radioactive material is implanted in the top layer of 5 microm thickness of an aluminum foil.

[Cartesian dualism or alchemy of medical routine practice]

Whereas alchemy postulated the unity of body and soul as early as in the 15th century, René Descartes developed an artificial separation of the body from the soul in the 17th century, a challenge that today's doctors continue to face. This problematic nature of dualism seems to be suitable for complicating the doctor's relationship with patients of different age groups. With the help of a screening technique and a semi-standardized interview 100 patients (25 women with RA aged > 65; 25 women with RA aged < 55; 25 women aged < 65 without RA and 25 women aged < 55 without RA) were examined with regard to their basic needs in the relationships with their doctor. The patients older than 65 showed characteristic psychophysical particularities and, as compared with patients younger than 55, 86% of them articulated the needs for security as primary need in the relationship with their doctor. Seventy-six percent of the younger patients articulated the need for passing on of information as primary need. To understand the world of the elderly means the handling of pseudo-morbidity, reduced capability, social death and disease as normality, means the acceptance of the need for a mainly emotional doctor-patient relationship. From the results efficient psycho-therapeutical findings can be recommended for the doctor's practical work with regard to "pitfalls," as well as for use as the basis for talks and for a method to use in dealing with elderly people.