49 research outputs found
A Universal Vertical Stellar Density Distribution Law for the Galaxy
We reduced the observational logarithmic space densities in the vertical
direction up to 8 kpc from the galactic plane, for stars with absolute
magnitudes (5,6], (6,7] and [5,10] in the fields #0952+5245 and SA114, to a
single exponential density law. One of three parameters in the quadratic
expression of the density law corresponds to the local space density for stars
with absolute magnitudes in question. There is no need of any definition for
scaleheights or population types. We confirm with the arguments of non-discrete
thin and thick discs for our Galaxy and propose a single structure up to
several kiloparsecs from the galactic plane. The logarithmic space densities
evaluated by this law for the ELAIS field fit to the observational ones.
Whereas, there are considerable offsets for the logarithmic space densities
produced by two sets of classical galactic model parameters from the
observational ones, for the same field.Comment: 9 pages, 1 figure and 10 tables, accepted for publication in
Astrophysics & Space Scienc
Predicting treatment benefit in multiple myeloma through simulation of alternative treatment effects
Many cancer treatments are associated with serious side effects, while they often only benefit a subset of the patients. Therefore, there is an urgent clinical need for tools that can aid in selecting the right treatment at diagnosis. Here we introduce simulated treatment learning (STL), which enables prediction of a patient’s treatment benefit. STL uses the idea that patients who received different treatments, but have similar genetic tumor profiles, can be used to model their response to the alternative treatment. We apply STL to two multiple myeloma gene expression datasets, containing different treatments (bortezomib and lenalidomide). We find that
Physics of rotation in stellar models
In these lecture notes, we present the equations presently used in stellar
interior models in order to compute the effects of axial rotation. We discuss
the hypotheses made. We suggest that the effects of rotation might play a key
role at low metallicity.Comment: 32 pages, 7 figures, lectures, CNRS school, will be published by
Springe
Safety assessment of essential medicines for elderly people: a bibliographic survey
Certain medicines are considered potentially inappropriate (PIM) for elderly people as they increase the risk of adverse drug events (ADE) and because safer alternative therapies are available on the market. In this context, in order to identify the instruments that assess the quality of medical prescriptions for elderly and to determine which drugs are considered PIM, a bibliographic survey was conducted in PUBMED, LILACS and PAHO databases, in February and March/2010. The search strategy included the use of health descriptors and a manual search in the references cited by selected papers. During the period of data collection, 15 instruments were identified. In 2012, with the publication of the update of Beers criteria, this instrument was included in the study. We identified 163 PIM of 25 therapeutic classes, of which 125 (76.7%) are marketed in Brazil. Of these, 31 (24.8%) are essential medicines (RENAME 2012), of which 13 have safer therapeutic equivalents and 19 (15.2%) are over-the-counter drugs. Data suggest the need for inclusion of safer alternatives for the elderly in the national list of essential medicines and the pharmaceutical care for early detection of ADE in this age group, in order to contribute to the safe use of medicines
Rapid and reproducible characterization of sickling during automated deoxygenation in sickle cell disease patients
In sickle cell disease (SCD), sickle hemoglobin (HbS) polymerizes upon deoxygenation,
resulting in sickling of red blood cells (RBCs). These sickled RBCs have strongly reduced
deformability, leading to vaso-occlusive crises and chronic hemolytic anemia. To date,
there are no reliable laboratory parameters or assays capable of predicting disease severity
or monitoring treatment effects. We here report on the oxygenscan, a newly developed
method to measure RBC deformability (expressed as Elongation Index - EI) as a function of
pO2. Upon a standardized, 22 minute, automated cycle of deoxygenation (pO2 median
16 mmHg ± 0.17) and reoxygenation, a number of clinically relevant parameters are produced in a highly reproducible manner (coefficients of variation <5%). In particular, physiological modulators of oxygen affinity, such as, pH and 2,3-diphosphoglycerate showed a
significant correlation (respectively R = ‑0.993 and R = 0.980) with Point of Sickling
(PoS5%), which is defined as the pO2 where a 5% decrease in EI is observed during deoxygenation. Furthermore, in vitro treatment with antisickling agents, including GBT440,
which alter the oxygen affinity of hemoglobin, caused a reproducible left-shift of the PoS,
indicating improved deformability at lower oxygen tensions. When RBCs from 21 SCD
patients were analyzed, we observed a significantly higher PoS in untreated homozygous
SCD patients compared to treated patients and other genotypes. We conclude that the
oxygenscan is a state-of-the-art technique that allows for rapid analysis of sickling behavior in SCD patients. The method is promising for personalized treatment, development of
new treatment strategies and could have potential in prediction of complications