991 research outputs found
The simulation model of growth and cell divisions for the root apex with an apical cell in application to Azolla pinnata
In contrast to seed plants, the roots of most ferns have a single apical cell which is the ultimate source of all cells in the root. The apical cell has a tetrahedral shape and divides asymmetrically. The root cap derives from the distal division face, while merophytes derived from three proximal division faces contribute to the root proper. The merophytes are produced sequentially forming three sectors along a helix around the root axis. During development, they divide and differentiate in a predictable pattern. Such growth causes cell pattern of the root apex to be remarkably regular and self-perpetuating. The nature of this regularity remains unknown. This paper shows the 2D simulation model for growth of the root apex with the apical cell in application to Azolla pinnata. The field of growth rates of the organ, prescribed by the model, is of a tensor type (symplastic growth) and cells divide taking principal growth directions into account. The simulations show how the cell pattern in a longitudinal section of the apex develops in time. The virtual root apex grows realistically and its cell pattern is similar to that observed in anatomical sections. The simulations indicate that the cell pattern regularity results from cell divisions which are oriented with respect to principal growth directions. Such divisions are essential for maintenance of peri-anticlinal arrangement of cell walls and coordinated growth of merophytes during the development. The highly specific division program that takes place in merophytes prior to differentiation seems to be regulated at the cellular level
Indications of early thermalization in relativistic heavy-ion collisions
The directed flow of particles emitted from the fireball created in a
heavy-ion collision is shown to be a very sensitive measure of the pressure
equilibration in the first 1 fm/c of the evolution. Performing a 3+1
dimensional relativistic hydrodynamic calculation with nonequilibrated
longitudinal and transverse pressures, we show that the directed flow is
strongly reduced if the pressure imbalance survives for even a short time.
Transverse momentum spectra, elliptic flow and interferometry correlation radii
are not very sensitive to this early pressure anisotropy. Comparison with the
data points toward a short equilibration time of the order of fm/c or
less
The assessment of cancer-related fatigue syndrome in patients with lung cancer during palliative chemotherapy
INTRODUCTION: Cancer-related fatigue is one of the most common problems of patients with lung cancer. The assessment of cancer- -related fatigue is therefore a significant medical problem in patients during treatment with palliative chemotherapy.
MATERIAL AND METHODS: The study included 100 patients during palliative chemotherapy because of lung cancer. The study was conducted in the Department of Pulmonary Diseases and Treatment of Lung Cancer in the Kuyavian and Pomeranian Centre of Pulmonology in Bydgoszcz, in the period from February to June 2016. The study used a socio-demographic questionnaire and Cancer Related Fatigue scale (CRF) consisting of 22 closed questions.
RESULTS: Men accounted for 68% of the study group, people with vocational education — 61%, and people living in the city — 61%. People aged 51–65 formed the largest group. The mean value for behavioural fatigue was 5.34 points, the sensory one — 5.44 points, cognitive/mood fatigue — 4.29 points (moderate levels), whereas mean value for affective fatigue was at a serious level — 5.89 points. The average severity of general fatigue was 5.2 points (moderate level of fatigue).
CONCLUSIONS: The moderate level of cancer-related fatigue occurs in half of patients treated with chemotherapy because of lung cancer, and lasts for several months. Behavioural, sensory, cognitive/mood and general fatigue have moderate levels but affective fatigue has a severe level. Radiation therapy affects the severity of cognitive/mood fatigue, lowers economic status, influences behavioural fatigue and education level, and has an effect on general fatigue. In multivariate analysis, only the reduction of economic status has a significant impact on the severity of fatigue.
 
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