102 research outputs found
PCN94 - Cost-effectiveness and preference for follow-up scenarios following breast cancer
OBJECTIVES: About one in every eight women in The Netherlands develops breast cancer. Every year, 11,000 new cases are registered and about 3500 women die of breast cancer. Prognosis after primary treatment for patients with breast cancer is improving. This leads to an increased number of patients in follow-up, which leads to increased workload. One of the main goals of follow-up is to improve the survival of patients. This study aims to determine a more individualized follow-up by modelling costeffectiveness of various follow-up scenarios and by determining individual preferences by using a discrete choice experiment (DCE). METHODS: A discrete-event state-transition model was developed to estimate the cost-effectiveness of all scenarios for all patient groups. In addition, a discrete choice experiment (DCE) was designed to establish patient preferences. The DCE incorporated three process attributes (duration of follow-up, frequency and type of consult) and data were collected in a sample of 125 breast cancer patients. Patients had to complete all 18 choice sets that were generated from the three attributes. RESULTS: The modelling study revealed recommendations for follow-up in different age categories. Patients younger than 40 and patients with unfavorable tumor characteristics (>3 lymph nodes, tumor size >2 cm) can benefit from a more intensive follow-up of five or possibly ten years. Patients older than 40 but younger than 70 years old sometimes benefit from a more intensive follow-up; e.g. when younger than 50 and tumor size >2 cm. The DCE, however, showed that patients chose maximum levels of follow-up independent from age and their individual clinical risk profile. Duration of follow-up and type of consult (either hospital visit or telephone) weighted approximately 0.43 and 0.50 respectively. The frequency of follow-up (either once or twice a year) was least important (0.07). CONCLUSIONS: The model showed that follow-up may be individualized according to risk profile and age. However, patients preferred long and intensive follow-up strategies after breast cancer treatment. Taking into account individual patient preferences it may be recommended to reduce the frequency of follow-up to once a year. The service delivery by nurse practioners is well appreciated and another means for improving cost-effective follow-up
A Model of Curvature-Induced Phase Transitions in Inflationary Universe
Chiral phase transitions driven by space-time curvature effects are
investigated in de Sitter space in the supersymmetric Nambu-Jona-Lasinio model
with soft supersymmetry breaking. The model is considered to be suitable for
the analysis of possible phase transitions in inflationary universe. It is
found that a restoration of the broken chiral symmetry takes place in two
patterns for increasing curvature : the first order and second order phase
transition respectively depending on initial settings of the four-body
interaction parameter and the soft supersymmetry breaking parameter. The
critical curves expressing the phase boundaries in these parameters are
obtained. Cosmological implications of the result are discussed in connection
with bubble formations and the creation of cosmic strings during the
inflationary era.Comment: 12 pages, 3 figures, REVTe
Effects induced by Apis mellifera venom and its components in experimental models of nociceptive and inflammatory pain
AbstractThe effects induced by Apis mellifera venom (AMV), melittin-free AMV, fraction with molecular mass < 10 kDa (F<10) or melittin in nociceptive and inflammatory pain models in mice were investigated. Subcutaneous administration of AMV (2, 4 or 6 mg/kg) or melittin-free AMV (1, 2 or 4 mg/kg) into the dorsum of mice inhibited both phases of formaldehyde-induced nociception. However, F<10 (2, 4 or 6 mg/kg) or melittin (2 or 3 mg/kg) inhibited only the second phase. AMV (4 or 6 mg/kg), but not F<10, melittin-free AMV or melittin, induced antinociception in the hot-plate model. Paw injection of AMV (0.05 or 0.10 mg), F<10 (0.05 or 0.1 mg) or melittin (0.025 or 0.050 mg) induced a nociceptive response. In spite of inducing nociception after paw injection, scorpion (Tityus serrulatus) or snake (Bothrops jararaca) venom injected into the dorsum of mice did not inhibit formaldehyde-induced nociception. In addition, AMV (6 mg/kg), but not F<10 (6 mg/kg) or melittin (3 mg/kg), inhibited formaldehyde paw oedema. Concluding, AMV, F<10 and melittin induce two contrasting effects: nociception and antinociception. AMV antinociception involves the action of different components and does not result from non-specific activation of endogenous antinociceptive mechanisms activated by exposure to noxious stimuli
Casimir Effect, Achucarro-Ortiz Black Hole and the Cosmological Constant
We treat the two-dimensional Achucarro-Ortiz black hole (also known as (1+1)
dilatonic black hole) as a Casimir-type system. The stress tensor of a massless
scalar field satisfying Dirichlet boundary conditions on two one-dimensional
"walls" ("Dirichlet walls") is explicitly calculated in three different vacua.
Without employing known regularization techniques, the expression in each
vacuum for the stress tensor is reached by using the Wald's axioms. Finally,
within this asymptotically non-flat gravitational background, it is shown that
the equilibrium of the configurations, obtained by setting Casimir force to
zero, is controlled by the cosmological constant.Comment: 20 pages, LaTeX, minor corrections, comments and clarifications
added, version to appear in Phys. Rev.
Direct band-gap crossover in epitaxial monolayer boron nitride
Hexagonal boron nitride is a large band-gap insulating material which complements the electronic and optical properties of graphene and the transition metal dichalcogenides. However, the intrinsic optical properties of monolayer boron nitride remain largely unexplored. In particular, the theoretically expected crossover to a direct-gap in the limit of the single monolayer is presently not con_rmed experimentally. Here, in contrast to the technique of exfoliating few-layer 2D hexagonal boron nitride, we exploit the scalable approach of high-temperature molecular beam epitaxy to grow high-quality monolayer boron nitride on graphite substrates. We combine deep-ultraviolet photoluminescence and reectance spectroscopy with atomic force microscopy to reveal the presence of a direct gap of energy 6.1 eV in the single atomic layers, thus con_rming a crossover to direct gap in the monolayer limit
Optical Light Curves of Supernovae
Photometry is the most easily acquired information about supernovae. The
light curves constructed from regular imaging provide signatures not only for
the energy input, the radiation escape, the local environment and the
progenitor stars, but also for the intervening dust. They are the main tool for
the use of supernovae as distance indicators through the determination of the
luminosity. The light curve of SN 1987A still is the richest and longest
observed example for a core-collapse supernova. Despite the peculiar nature of
this object, as explosion of a blue supergiant, it displayed all the
characteristics of Type II supernovae. The light curves of Type Ib/c supernovae
are more homogeneous, but still display the signatures of explosions in massive
stars, among them early interaction with their circumstellar material. Wrinkles
in the near-uniform appearance of thermonuclear (Type Ia) supernovae have
emerged during the past decade. Subtle differences have been observed
especially at near-infrared wavelengths. Interestingly, the light curve shapes
appear to correlate with a variety of other characteristics of these
supernovae. The construction of bolometric light curves provides the most
direct link to theoretical predictions and can yield sorely needed constraints
for the models. First steps in this direction have been already made.Comment: To be published in:"Supernovae and Gamma Ray Bursters", Lecture Notes
in Physics (http://link.springer.de/series/lnpp
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