286 research outputs found
Plume Development of the Shoemaker-Levy 9 Comet Impact
We have studied plume formation after a Jovian comet impact using the ZEUS-MP
2 hydrodynamics code. The three-dimensional models followed objects with 500,
750, and 1000 meter diameters. Our simulations show the development of a fast,
upward-moving component of the plume in the wake of the impacting comet that
"pinches off" from the bulk of the cometary material ~50 km below the 1 bar
pressure level, ~100 km above the depth of greatest mass and energy deposition.
The fast-moving component contains about twice the mass of the initial comet,
but consists almost entirely (>99.9%) of Jovian atmosphere rather than cometary
material. The ejecta rise mainly along the impact trajectory, but an additional
vertical velocity component due to buoyancy establishes itself within seconds
of impact, leading to an asymmetry in the ejecta with respect to the entry
trajectory. The mass of the upward-moving component follows a velocity
distribution M(>v) approximately proportional to v^-1.4 (v^-1.6 for the 750 m
and 500 m cases) in the velocity range 0.1 < v < 10 km/s.Comment: 5 pages, 4 figures. Accepted for publication in The Astrophysical
Journa
Coping Strategies of Elite Hungarian Junior Handball Players
Several studies provided instruments, with the possibility to measure self-assessment and coping strategies. This study aimed to study differences in coping strategies by age groups and gender in handball players. For psychological profile the Athletic Coping Skills Inventory (ACSI-28) was applied, at elite Hungarian junior handball teams (n=288) in 2016-2017. On the scales Coping with Adversity and Freedom From worry males acquired significantly higher average values, females showed higher mean values of Goal Setting / Mental Preparation and Coachability. On Freedom from Worry, the oldest players performed the best, Coachability was highest in the youngest group. High values of Concentration were measured by playmakers, which was significantly higher than that of other offensive roles. With the results of our study, we would like to draw attention to the fact that for successful preparation, the knowledge of the athlete's coping skills and their self-knowledge are in dispensable.Jelen tanulmányunkban magyar utánpótlás korú (14-19 éves) kézilabdázók (n=288) sportolói megküzdési stratégiáit vizsgáltuk a nemek, életkorok és a kézilabda posztok tekintetében, AthleticCopingSkillsInventory (ACSI-28) segítségével. A Csapásokkal való megküzdés (11,69 vs. 11,00; F=2,670 p<0,01) és a Szorongásmentesség (9,94 vs. 9,12; F=2,670 p<0,01) skálákon a férfiak értek el szignifikánsan magasabb átlagot. Ezzel szemben a nők magasabb átlagot mutattak a Célkitűzés/mentális felkészültség (12,12 vs. 11,56; F=-2,121 p<0,05) és az Edző által irányíthatóság (13,28 vs. 12,12; F=-4,107 p<0,01). A Szorongásmentesség(10,55 vs. 9,88 vs. 8,83; F=6,880 p<0,01) skálán a legidősebb játékosok érték el a legmagasabb értékeket. Az Edző által irányíthatóság (F=9,617 p<0,01) a legfiatalabbak körében volt a legmagasabb. A kézilabda posztok alapján megállapíthatjuk, hogy a Koncentráció (F=2,612 p<0,05) és az Önbizalom/teljesítmény motiváció (F=3,067 p<0,05) skálákon mutatkoztak szignifikáns különbségek a csoportátlagokban. A Koncentráció tekintetében az irányítóknál látunk magas átlagot, amely szignifikánsan magasabb, mint a többi támadó poszton játszók esetében.Az Önbizalom esetében a szélsők csoportjában találhatóak a legmagasabb értékek. A tanulmányunk eredményeivel arra szeretnék felhívni a figyelmet, hogy az edzőknek a sikeres felkészülés érdekében figyelembe kell venniük a játékosaik nemét, életkorát, posztját, hiszen a teljesítmény növeléséhez elengedhetetlen a sportoló megküzdési képességeinek ismerete és a játékos önismerete
A ready-to-use dry powder formulation based on protamine nanocarriers for pulmonary drug delivery
The use of oral antibiotic therapy for the treatment of respiratory diseases as tuberculosis has promoted the appearance of side effects as well as resistance to these treatments. The low solubility, high metabolism, and degradation of drugs as rifabutin, have led to the use of combined and prolonged therapies, which difficult patient compliance. In this work, we develop inhalable formulations from biomaterials such as protamine to improve the therapeutic effect. Rifabutin-loaded protamine nanocapsules (NCs) were prepared by solvent displacement method and were physico-chemically characterized and evaluated for their dissolution, permeability, stability, cytotoxicity, hemocompatibility, internalization, and aerodynamic characteristics after a spray-drying procedure. Protamine NCs presented a size of around 200 nm, positive surface charge, and drug association up to 54%. They were stable as suspension under storage, as well as in biological media and as a dry powder after lyophilization in the presence of mannitol. Nanocapsules showed a good safety profile and cellular uptake with no tolerogenic effect on macrophages and showed good compatibility with red blood cells. Moreover, the aerodynamic evaluation showed a fine particle fraction deposition up to 30% and a mass median aerodynamic diameter of about 5 µm, suitable for the pulmonary delivery of therapeutics. © 202
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