Supercritical mixtures of ethanol (EtOH) and carbon dioxide (CO2) are classified as type-I mixtures, with complete macroscopic miscibility. However, differences in molecular polarity and interactions suggest a distinct phase behavior at the microscopic level. Here, we combine small angle X-ray scattering experiments and molecular dynamics (MD) simulations to investigate the microscopic structure of EtOH-CO2 mixtures under supercritical conditions. The structure factor exhibits nonlinear composition-dependent behavior, revealing pronounced local density fluctuations. The complementary MD simulations, using optimized force field parameters, provide atomistic insight, showing that EtOH forms self-associated, hydrogen-bonded aggregates, while CO2 remains more uniformly distributed. Cluster analysis identifies a preferential EtOH-rich composition exceeding the bulk average, governed by a balance between energetic and entropic competition. These results demonstrate that, contrary to macroscopic expectations, the mixture exhibits significant microscopic heterogeneity and immiscibility, which may influence solubility, reactivity, transport properties, and thermodynamic response functions. These findings challenge the conventional views of type-I fluids and emphasize the necessity of revising mixture states and considering molecular polarity.

Supercritical carbon dioxide (sCO2) forms structural heterogeneities arising from molecular clusters, which can be quantified with Small Angle X-ray Scattering (SAXS) measurements. We perform SAXS of sCO2 to examine how the cluster morphology (size and shape) is related to the local thermodynamic condition. We find that the primary cluster shape shifts from sphere-like near the Widom line to disk-like further away. By relating cluster morphology to heat capacity, we show how the cluster structure affects the thermodynamic response functions in supercritical fluids.

Supercritical fluids (SCFs) can be found in a variety of environmental and industrial processes. They exhibit an anomalous thermodynamic behavior, which originates from their fluctuating heterogeneous micro-structure. Characterizing the dynamics of these fluids at high temperature and high pressure with nanometer spatial and picosecond temporal resolution has been very challenging. The advent of hard x-ray free electron lasers has enabled the development of novel multi-pulse ultrafast x-ray scattering techniques, such as x-ray photon correlation spectroscopy (XPCS) and x-ray pump x-ray probe (XPXP). These techniques offer new opportunities for resolving the ultrafast microscopic behavior in SCFs at unprecedented spatiotemporal resolution, unraveling the dynamics of their micro-structure. However, harnessing these capabilities requires a bespoke high-pressure and high-temperature sample system that is optimized to maximize signal intensity and address instrument-specific challenges, such as drift in beamline components, x-ray scattering background, and multi-x-ray-beam overlap. We present a pressure cell compatible with a wide range of SCFs with built-in optical access for XPCS and XPXP and discuss critical aspects of the pressure cell design, with a particular focus on the design optimization for XPCS.

The small-angle x-ray scattering beam line BL4-2 at the Stanford Synchrotron Radiation Lightsource (SSRL) is a permanent experimental station dedicated to structural biology and biophysics, providing state-of-the-art experimental facilities for structural studies on nucleic acids, proteins, protein assemblies, virus particles, biological fibers, lipid membranes and their complexes. The instrument features a variable sample to detector distance (from 0.25m – 3.5m, in seven discrete steps), a state-of-the-art pixel array detector (Pilatus3 X 1M) with high image frame rate and dynamic rang as well as large area CCD detector (Rayonix MX225HE) with high photon detection efficiency, small pixel size and gap-less images. Specialized sample handling devices for variety of different SAXS experiments are available for use at the beam line. This includes a fully automated high-throughput sample delivery robot for biological macromolecular solutions. The robot automatically performs all steps necessary for high quality data collection and is connected to a software pipeline for data reduction and initial analysis in real time, summarizing the results for the user in an easy to view html table. For aggregation prone samples or weakly bound complexes a size-exclusion chromatography setup can be directly coupled to the instrument to provide the highest sample quality for the SAXS data collection. The chromatography setup features a tandem pump system and automatic sample injection that connected to the data acquisition system providing fully automated SEC-SAXS data collection. In addition to the static solution scattering measurements we also provide state-of-the-art instrumentation for time resolved experiments on biological systems on the millisecond time scale. Our stopped-flow device has been optimized to substantially reduce the required sample volume in order to allow time-resolved measurements on systems that are difficult to produce in larger amounts. Here we will discuss recent upgrades and technological developments at the beamline.

Femtosecond X-ray laser pulses are used to probe the structure of liquid water in micrometre-sized droplets that have been cooled below the homogeneous ice nucleation temperature, revealing the existence of metastable bulk liquid water down to temperatures of 227 kelvin.

Objectives. This study aimed to determine patient-related predictors of treatment satisfaction in fibromyalgia syndrome (FMS)-patients.Methods. In a cross-sectional survey, participants with self-reported diagnosis of FMS were recruited by FMS-self help organisations and clinical institutions. The patients answered demographic and medical questionnaires, the Fibromyalgia Survey Questionnaire (FSQ) including the Somatic Severity Score (SSS) and Widespread Pain Index (WPI), the Patient Health Questionnaire (PHQ-4), and rated their treatment satisfaction on an 11-point Likert scale. The impact of patient-related variables (age, gender, partnership, educational level, time since onset of pain, time since FMS-diagnosis, health status since diagnosis, membership in FMS self-help organisations, polysymptomatic distress, anxiety and depression) and types of treatment on treatment satisfaction were tested by a multiple regression analysis.Results. The study sample (n=1651 patients) was composed mainly of middle-aged women with a long disease history, and 83.9% fulfilled the American College of Rheumatology diagnostic criteria of 2010. There was considerate variety regarding treatment satisfaction in FMS-patients, 14.8% reported no, 31.7% low, 40.8% moderate and 12.7% high satisfaction. Higher satisfaction was predicted by longer time since FMS diagnosis (p=0.03), improved health status since FMS-diagnosis (p<0.0001), lower depression score (p=0.005) and higher amount of active therapies (p<0.0001). Other sociodemographic (age, gender etc.) and disease-related variables (polysymptomatic distress intensity) did not influence treatment satisfaction.Conclusion. The results of the study illustrate the influence of patient-related factors on treatment satisfaction. Treating comorbid depression and enabling patients to actively cope with the disease might prove successful in improving treatment satisfaction of FMS-patients.

Aus Deutschland lagen keine Daten zu demografischen und klinischen Charakteristika der Mitglieder von Fibromyalgiesyndrom (FMS)-Selbsthilfegruppen vor.

Verbraucherberichte liefern Informationen über den Nutzen und Schaden von Therapieverfahren in der klinischen Routineversorgung. Wir berichten über den ersten Verbraucherbericht von Fibromyalgiesyndrom(FMS)-Betroffenen in Europa.

The scheduled update to the German S3 guidelines on fibromyalgia syndrome (FMS) by the Association of the Scientific Medical Societies ("Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften", AWMF; registration number 041/004) was planned starting in March 2011.The development of the guidelines was coordinated by the German Interdisciplinary Association for Pain Therapy ("Deutsche Interdisziplinaren Vereinigung fur Schmerztherapie", DIVS), 9 scientific medical societies and 2 patient self-help organizations. Eight working groups with a total of 50 members were evenly balanced in terms of gender, medical field, potential conflicts of interest and hierarchical position in the medical and scientific fields.Literature searches were performed using the Medline, PsycInfo, Scopus and Cochrane Library databases (until December 2010). The grading of the strength of the evidence followed the scheme of the Oxford Centre for Evidence-Based Medicine. The formulation and grading of recommendations was accomplished using a multi-step, formal consensus process. The guidelines were reviewed by the boards of the participating scientific medical societies.Low-to-moderate intensity aerobic exercise and strength training are strongly recommended. Chiropractic, laser therapy, magnetic field therapy, massage and transcranial current stimulation are not recommended.The English full-text version of this article is available at SpringerLink (under "Supplemental").

Die planmäßige Aktualisierung der S3-Leitlinie zum Fibromyalgiesyndrom (FMS; AWMF-Registernummer 041/004) wurde ab März 2011 vorgenommen.

The Fibromyalgia Survey Questionnaire (FSQ) assesses the key symptoms of fibromyalgia syndrome. The FSQ can be administrated in survey research and settings where the use of interviews to evaluate the number of pain sites and extent of somatic symptom intensity and tender point examination would be difficult. We validated the FSQ in a cross-sectional survey with FMS patients. In a cross-sectional survey, participants with physician diagnosis of FMS were recruited by FMS-self help organisations and nine clinical institutions of different levels of care. Participants answered the FSQ (composed by the Widespread Pain Index [WPI] and the Somatic Severity Score [SSS]) assessing the Fibromyalgia Survey Diagnostic Criteria (FSDC) and the Patient Health Questionnaire PHQ 4. American College of Rheumatology 1990 classification criteria were assessed in a subgroup of participants. 1,651 persons diagnosed with FMS were included into analysis. The acceptance of the FSQ-items ranged between 78.9 to 98.1% completed items. The internal consistency of the items of the SSS ranged between 0.75-0.82. 85.5% of the study participants met the FSDC. The concordance rate of the FSDC and ACR 1990 criteria was 72.7% in a subsample of 128 patients. The Pearson correlation of the SSS with the PHQ 4 depression score was 0.52 (p<0.0001) and with the PHQ anxiety score was 0.51 (p<0.0001) (convergent validity). 64/202 (31.7%) of the participants not meeting the FSDC criteria and 152/1283 (11.8%) of the participants meeting the FSDC criteria reported an improvement (slightly too very much better) in their health status since FMS-diagnosis (Chi(2) = 55, p<0.0001) (discriminant validity). The study demonstrated the feasibility of the FSQ in a cross-sectional survey with FMS-patients. The reliability, convergent and discriminant validity of the FSQ were good. Further validation studies of the FSQ in clinical and general population settings are necessary.

Background: Consumer surveys provide information on effectiveness and side effects of medical interventions in routine clinical care. A report of fibromyalgia syndrome (FMS) consumers has not been carried out in Europe.Methods: The study was carried out from November 2010 to April 2011. Participants diagnosed with FMS rated the effectiveness and side effects of pharmacological and non-pharmacological FMS interventions on a 0 to 10 scale, with 10 being most efficacious (harmful). The questionnaire was distributed by the German League for people with Arthritis and Rheumatism and the German Fibromyalgia Association to their members and to all consecutive FMS patients of nine clinical centers of different levels of care.Results: 1661 questionnaires (95% women, mean age 54 years, mean duration since FMS diagnosis 6.8 years) were analysed. The most frequently used therapies were self-management strategies, prescription pain medication and aerobic exercise. The highest average effectiveness was attributed to whole body and local warmth therapies, thermal bathes, FMS education and resting. The highest average side effects were attributed to strong opioids, local cold therapy, gamma-amino-butyric acid analogues (pregabalin and gabapentin), tramadol and opioid transdermal systems.Conclusion: The German fibromyalgia consumer reports highlight the importance of non-pharmcological therapies in the long-term management of FMS, and challenges the strong recommendations for drug therapies given by FMS-guidelines.