Hydrogen-Helium Mixtures at High Pressure

The properties of hydrogen-helium mixtures at high pressure are crucial to address important questions about the interior of Giant planets e.g. whether Jupiter has a rocky core and did it emerge via core accretion? Using path integral Monte Carlo simulations, we study the properties of these mixtures as a function of temperature, density and composition. The equation of state is calculated and compared to chemical models. We probe the accuracy of the ideal mixing approximation commonly used in such models. Finally, we discuss the structure of the liquid in terms of pair correlation functions.Comment: Proceedings article of the 5th Conference on Cryocrystals and Quantum Crystals in Wroclaw, Poland, submitted to J. Low. Temp. Phys. (2004

Factors associated with worse lung function in cystic fibrosis patients with persistent staphylococcus aureus

Background Staphylococcus aureus is an important pathogen in cystic fibrosis (CF). However, it is not clear which factors are associated with worse lung function in patients with persistent S. aureus airway cultures. Our main hypothesis was that patients with high S. aureus density in their respiratory specimens would more likely experience worsening of their lung disease than patients with low bacterial loads. Methods Therefore, we conducted an observational prospective longitudinal multi-center study and assessed the association between lung function and S. aureus bacterial density in respiratory samples, co-infection with other CF-pathogens, nasal S. aureus carriage, clinical status, antibiotic therapy, IL-6- and IgG-levels against S. aureus virulence factors. Results 195 patients from 17 centers were followed; each patient had an average of 7 visits. Data were analyzed using descriptive statistics and generalized linear mixed models. Our main hypothesis was only supported for patients providing throat specimens indicating that patients with higher density experienced a steeper lung function decline (p<0.001). Patients with exacerbations (n = 60), S. aureus small-colony variants (SCVs, n = 84) and co-infection with Stenotrophomonas maltophilia (n = 44) had worse lung function (p = 0.0068; p = 0.0011; p = 0.0103). Patients with SCVs were older (p = 0.0066) and more often treated with trimethoprim/sulfamethoxazole (p = 0.0078). IL-6 levels positively correlated with decreased lung function (p<0.001), S. aureus density in sputa (p = 0.0016), SCVs (p = 0.0209), exacerbations (p = 0.0041) and co-infections with S. maltophilia (p = 0.0195) or A. fumigatus (p = 0.0496). Conclusions In CF-patients with chronic S. aureus cultures, independent risk factors for worse lung function are high bacterial density in throat cultures, exacerbations, elevated IL-6 levels, presence of S. aureus SCVs and co-infection with S. maltophilia

Effects of Recruitment Maneuver on Atelectasis in Anesthetized Children

Background: General anesthesia is known to promote atelectasis formation. High inspiratory pressures are required to reexpand healthy but collapsed alveoli. However, in the absence of positive end-expiratory pressure (PEEP), reexpanded alveoli collapse again. Using magnetic resonance imaging, the impact of an alveolar recruitment strategy on the amount and distribution of atelectasis was tested. Methods: The authors prospectively randomized 24 children who met American Society of Anesthesiologists physical status I or II criteria, were aged 6 months-6 yr, and were undergoing cranial magnetic resonance imaging into three groups. After anesthesia induction, in the alveolar recruitment strateg

Positive Pre-cystectomy Biopsies of the Prostatic Urethra or Bladder Neck Do Not Necessarily Preclude Orthotopic Bladder Substitution.

We investigated the influence of positive pre-cystectomy biopsies of the prostatic urethra in males and the bladder neck in females on urethral recurrence, cancer specific and overall survival, and functional outcomes after orthotopic bladder substitution. We retrospectively analyzed the records of 803 consecutive patients, including 703 males and 100 females, who underwent orthotopic bladder substitution as well as pre-cystectomy biopsy of the prostatic urethra in males and the bladder neck in females, at our institution between April 1986 and December 2017. Pre-cystectomy biopsies were negative in 755 of the 803 patients (94%) (group 1) and positive in 48 (6%) (group 2). Biopsies in group 2 revealed carcinoma in situ in 35 of the 48 cases (73%), pTaG1/G2 in 5 (10%) and pTaG3/pT1G3 in 8 (17%). Median followup was 64 months (IQR 21-128). At a median followup of 56 months (IQR 18-127) urethral recurrence developed in 45 of the 803 patients (5.6%), including 30 of the 755 (4%) in group 1 and 15 of the 48 (31.3%) in group 2 (p &lt;0.001). Only 10 of the 45 patients (22%) with urethral recurrence required salvage urethrectomy while locally conservative treatment was successful in 27 (60%). Of the remaining 8 patients 6 of 45 (13%) underwent synchronous palliative chemotherapy and 2 of 45 (4%) refused treatment. Multivariate regression analysis revealed a higher risk of urethral recurrence if patients had positive pre-cystectomy biopsies (group 2 HR 6.49, 95% CI 3.33-12.62, p &lt;0.001) or received neoadjuvant or adjuvant chemotherapy (HR 3.05, 95% CI 1.66-5.59, p &lt;0.001). Cancer specific and overall survival as well as functional outcomes were similar in the 2 groups. Positive pre-cystectomy biopsies prior to orthotopic bladder substitution increased the urethral recurrence rate but did not lower cancer specific or overall survival. Most urethral recurrences were managed successfully by local treatment. Orthotopic bladder substitution is an option in highly selected patients with positive, noninvasive pre-cystectomy biopsies, provided that they undergo regular followup including urethral cytology

Protocol for a randomized, placebo-controlled, double-blind clinical trial investigating sacral neuromodulation for neurogenic lower urinary tract dysfunction

Background: Sacral neuromodulation has become a well-established and widely accepted treatment for refractory non-neurogenic lower urinary tract dysfunction, but its value in patients with a neurological cause is unclear. Although there is evidence indicating that sacral neuromodulation may be effective and safe for treating neurogenic lower urinary tract dysfunction, the number of investigated patients is low and there is a lack of randomized controlled trials. Methods and design: This study is a prospective, randomized, placebo-controlled, double-blind multicenter trial including 4 sacral neuromodulation referral centers in Switzerland. Patients with refractory neurogenic lower urinary tract dysfunction are enrolled. After minimally invasive bilateral tined lead placement into the sacral foramina S3 and/or S4, patients undergo prolonged sacral neuromodulation testing for 3-6 weeks. In case of successful (defined as improvement of at least 50% in key bladder diary variables (i.e. number of voids and/or number of leakages, post void residual) compared to baseline values) prolonged sacral neuromodulation testing, the neuromodulator is implanted in the upper buttock. After a 2 months post-implantation phase when the neuromodulator is turned ON to optimize the effectiveness of neuromodulation using sub-sensory threshold stimulation, the patients are randomized in a 1:1 allocation in sacral neuromodulation ON or OFF. At the end of the 2 months double-blind sacral neuromodulation phase, the patients have a neuro-urological re-evaluation, unblinding takes place, and the neuromodulator is turned ON in all patients. The primary outcome measure is success of sacral neuromodulation, secondary outcome measures are adverse events, urodynamic parameters, questionnaires, and costs of sacral neuromodulation. Discussion: It is of utmost importance to know whether the minimally invasive and completely reversible sacral neuromodulation would be a valuable treatment option for patients with refractory neurogenic lower urinary tract dysfunction. If this type of treatment is effective in the neurological population, it would revolutionize the management of neurogenic lower urinary tract dysfunction

A blueprint for mapping and modelling ecosystem services

The inconsistency in methods to quantify and map ecosystem services challenges the development of robust values of ecosystem services in national accounts and broader policy and natural resource management decision-making. In this paper we develop and test a blueprint to give guidance on modelling and mapping ecosystem services. The primary purpose of this blueprint is to provide a template and checklist of information needed for those beginning an ecosystem service modelling and mapping study. A secondary purpose is to provide, over time, a database of completed blueprints that becomes a valuable information resource of methods and information used in previous modelling and mapping studies. We base our blueprint on a literature review, expert opinions (as part of a related workshop organised during the 5th ESP conference2 ) and critical assessment of existing techniques used to model and map ecosystem services. While any study that models and maps ecosystem services will have its unique characteristics and will be largely driven by data and model availability, a tool such as the blueprint presented here will reduce the uncertainty associated with quantifying ecosystem services and thereby help to close the gap between theory and practice