329 research outputs found
Wall-Fluid and Liquid-Gas Interfaces of Model Colloid-Polymer Mixtures by Simulation and Theory
We perform a study of the interfacial properties of a model suspension of
hard sphere colloids with diameter and non-adsorbing ideal polymer
coils with diameter . For the mixture in contact with a planar hard
wall, we obtain from simulations the wall-fluid interfacial free energy,
, for size ratios and 1, using
thermodynamic integration, and study the (excess) adsorption of colloids,
, and of polymers, , at the hard wall. The interfacial
tension of the free liquid-gas interface, , is obtained following
three different routes in simulations: i) from studying the system size
dependence of the interfacial width according to the predictions of capillary
wave theory, ii) from the probability distribution of the colloid density at
coexistence in the grand canonical ensemble, and iii) for statepoints where the
colloidal liquid wets the wall completely, from Young's equation relating
to the difference of wall-liquid and wall-gas interfacial
tensions, . In addition, we calculate , and using density functional theory and a scaled particle
theory based on free volume theory. Good agreement is found between the
simulation results and those from density functional theory, while the results
from scaled particle theory quantitatively deviate but reproduce some essential
features. Simulation results for obtained from the three
different routes are all in good agreement. Density functional theory predicts
with good accuracy for high polymer reservoir packing fractions,
but yields deviations from the simulation results close to the critical point.Comment: 23 pages, 10 figures, REVTEX. Fig 5a changed. Final versio
All-age hospitalization rates in coal seam gas areas in Queensland, Australia, 1995–2011
Background: Unconventional natural gas development (UNGD) is expanding globally, with Australia expanding development in the form of coal seam gas (CSG). Residents and other interest groups have voiced concerns about the potential environmental and health impacts related to CSG. This paper compares objective health outcomes from three study areas in Queensland, Australia to examine potential environmentally-related health impacts. Methods: Three study areas were selected in an ecologic study design: A CSG area, a coal mining area, and a rural/agricultural area. Admitted patient data, as well as population data and additional factors, were obtained for each calendar year from 1995 through 2011 to calculate all-age hospitalization rates and age-standardized rates in each of these areas. The three areas were compared using negative binomial regression analyses (unadjusted and adjusted models) to examine increases over time of hospitalization rates grouped by primary diagnosis (19 ICD chapters), with rate ratios serving to compare the within-area regression slopes between the areas. Results: The CSG area did not have significant increases in all-cause hospitalization rates over time for all-ages compared to the coal and rural study areas in adjusted models (RR: 1.02, 95 % CI: 1.00-1.04 as compared to the coal mining area; RR: 1.01, 95 % CI: 0.99-1.04 as compared to the rural area). While the CSG area did not show significant increases in specific hospitalization rates compared to both the coal mining and rural areas for any ICD chapters in the adjusted models, the CSG area showed increases in hospitalization rates compared only to the rural area for neoplasms (RR: 1.09, 95 % CI: 1.02-1.16) and blood/immune diseases (RR: 1.14, 95 % CI: 1.02-1.27). Conclusions: This exploratory study of all-age hospitalization rates for three study areas in Queensland suggests that certain hospital admissions rates increased more quickly in the CSG study area than in other study areas, particularly the rural area, after adjusting for key sociodemographic factors. These findings are an important first step in identifying potential health impacts of CSG in the Australian context and serve to generate hypotheses for future studies
Understanding the experience of group singing for couples where one partner has a diagnosis of dementia
Purpose of study: There is a continuing interest around the use of group singing in dementia care. Although studies generally indicate positive outcomes, limited research has been carried out from a relational perspective, which places the couple relationship in a central position. This study aimed to better understand how group singing benefits people with dementia and their partners.
Design and Methods: Interview data from 17 couples (N = 34) with one member having dementia, who participated in a range of different types of singing groups, were analysed using grounded theory methodology.
Results: Five key areas were identified, resulting in the development of the group singing model in dementia for couple dyads. Group singing was experienced as being both joyful and accessible. The accessibility of singing, combined with effective facilitation, created an environment for active participation and enjoyment. The group effect mediated further benefits for the person with dementia and for the caregiver which, when combined, increased benefits for the couple through participation in new experiences.
Implications: An opportunity for couples to share in-the-moment creative expression and the positive affect of artistic creation circumventing cognitive impairment is likely to contribute positively to the experience of the relationship. A more refined understanding of shared creative processes in relationship-centred models of care could inform dementia support services. Future research would benefit from longitudinally exploring the links between creativity in couples and relationship resilience
Имитационное моделирование технологии управления процессом производства
Предложено использование комплекса имитационного моделирования для получения информации при контроле функционирования и управлении технологическим процессом производства.Запропоновано використання комплексу імітаційного моделювання для одержання інформації при контролюванні функціонування та управління технологічним процесом виробництва.Complex of simulation modeling for obtaining information when checking an operation and control of technological process of production is offered to use
The R136 star cluster dissected with Hubble Space Telescope/STIS. I. Far-ultraviolet spectroscopic census and the origin of HeII 1640 in young star clusters
We introduce a HST/STIS stellar census of R136a, the central ionizing star
cluster of 30 Doradus. We present low resolution far-ultraviolet STIS/MAMA
spectroscopy of R136 using 17 contiguous 52x0.2 arcsec slits which together
provide complete coverage of the central 0.85 parsec (3.4 arcsec). We provide
spectral types of 90% of the 57 sources brighter than m_F555W = 16.0 mag within
a radius of 0.5 parsec of R136a1, plus 8 additional nearby sources including
R136b (O4\,If/WN8). We measure wind velocities for 52 early-type stars from CIV
1548-51, including 16 O2-3 stars. For the first time we spectroscopically
classify all Weigelt & Baier members of R136a, which comprise three WN5 stars
(a1-a3), two O supergiants (a5-a6) and three early O dwarfs (a4, a7, a8). A
complete Hertzsprung-Russell diagram for the most massive O stars in R136 is
provided, from which we obtain a cluster age of 1.5+0.3_-0.7 Myr. In addition,
we discuss the integrated ultraviolet spectrum of R136, and highlight the
central role played by the most luminous stars in producing the prominent HeII
1640 emission line. This emission is totally dominated by very massive stars
with initial masses above ~100 Msun. The presence of strong HeII 1640 emission
in the integrated light of very young star clusters (e.g A1 in NGC 3125)
favours an initial mass function extending well beyond a conventional upper
limit of 100 Msun. We include montages of ultraviolet spectroscopy for LMC O
stars in the Appendix. Future studies in this series will focus on optical
STIS/CCD medium resolution observations.Comment: 20 pages plus four Appendices providing LMC UV O spectral templates,
UV spectral atlas in R136, wind velocities of LMC O stars and photometry of
additional R136 source
Feasibility and effectiveness of trifluridine/tipiracil in metastatic colorectal cancer: real-life data from The Netherlands
Background: The RECOURSE trial showed clinical efficacy for trifluridine/tipiracil for refractory metastatic colorectal cancer patients. We assessed the feasibility and effectiveness of trifluridine/tipiracil in daily clinical practice in The Netherlands. Methods: Medical records of patients from 17 centers treated in the trifluridine/tipiracil compassionate use program were reviewed and checked for RECOURSE eligibility criteria. Baseline characteristics, safety, and survival times were compared, and prespecified baseline characteristics were tested in multivariate analyses for prognostic significance on overall survival (OS). Results: A total of 136 patients with a median age of 62 years were analyzed. Forty-three patients (32%) did not meet the RECOURSE eligibility criteria for not having received all prior standard treatments (n = 35, 26%) and/or ECOG performance status (PS) 2 (n = 12, 9%). The most common grade ≥3 toxicities were neutropenia (n = 44, 32%), leukopenia (n = 8, 6%), anemia (n = 7, 5%), and fatigue (n = 7, 5%). Median progression-free survival (PFS) and median OS were 2.1 (95% CI, 1.8–2.3) and 5.4 months (95% CI, 4.0–6.9), respectively. Patients with ECOG PS 2 had a worse median OS (3.2 months) compared to patients with ECOG PS 0–1 (5.9 months). ECOG PS, KRAS-mutation status, white blood cell count, serum lactate dehydrogenase, and alkaline phosphatase were prognostic factors for OS. Conclusions: Our data show that treatment with trifluridine/tipiracil in daily clinical practice is feasible and safe. Differences in patient characteristics between our population and the RECOURSE study population should be taken into account in the interpretation of survival data. Our results argue against the use of trifluridine/tipiracil in patients with ECOG PS 2. Funding: Johannes J.M. Kwakman received an unrestricted research grant from Servier
Modeling Personalized Adjuvant TreaTment in EaRly stage coloN cancer (PATTERN)
Aim: To develop a decision model for the population-level evaluation of strategies to improve the selection of stage II colon cancer (CC) patients who benefit from adjuvant chemotherapy. Methods: A Markov cohort model with a one-month cycle length and a lifelong time horizon was developed. Five health states were included; diagnosis, 90-day mortality, death other causes, recurrence and CC death. Data from the Netherlands Cancer Registry were used to parameterize the model. Transition probabilities were estimated using parametric survival models including relevant clinical and pathological covariates. Subsequently, biomarker status was implemented using external data. Treatment effect was incorporated using pooled trial data. Model development, data sources used, parameter estimation, and internal and external validation are described in detail. To illustrate the use of the model, three example strategies were evaluated in which allocation of treatment was based on (A) 100% adherence to the Dutch guidelines, (B) observed adherence to guideline recommendations and (C) a biomarker-driven strategy. Results: Overall, the model showed good internal and external validity. Age, tumor growth, tumor sidedness, evaluated lymph nodes, and biomarker status were included as covariates. For the example strategies, the model predicted 83, 87 and 77 CC deaths after 5 years in a cohort of 1000 patients for strategies A, B and C, respectively. Conclusion: This model can be used to evaluate strategies for the allocation of adjuvant chemotherapy in stage II CC patients. In future studies, the model will be used to estimate population-level long-term health gain and cost-effectiveness of biomarker-based selection strategies
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