Millimeter-sized silicate spherules embedded in primitive meteorites, namely, "chondrules," are the primary solid component of the early solar nebula. They exhibit distinctive solidification textures, formed through rapid cooling from a molten state. The formation conditions of these textures have primarily been inferred on the basis of dynamic crystallization experiments; however, the theoretical verification of the solidification process has been largely neglected.
View Article and Find Full Text PDFRadiol Case Rep
December 2024
We report a case involving an aortic arch anomaly that has not been previously documented. The patients were a 76-year-old female who was urgently transported to the hospital because of a sudden disturbance of consciousness. Neurological symptoms indicated impending brain herniation, and the patient was diagnosed with hypertensive intracerebral hemorrhage (left putamen-thalamus) and acute hydrocephalus, thereafter she died approximately 6 hours after arrival.
View Article and Find Full Text PDFWe propose a kinetic mathematical model of the oscillatory compositional zoning profile recorded in minerals based on the crystal growth suppression induced by impurities. Notably, the presence of a small amount of impurities significantly inhibits crystal growth, and a growth inhibition mechanism called the pinning effect is widely accepted. Here we show that a model that considers the pinning effect and adsorption/desorption kinetics of impurities on the crystal surface can reproduce the oscillatory compositional zoning.
View Article and Find Full Text PDFProc Jpn Acad Ser B Phys Biol Sci
June 2022
Presented here are the observations and interpretations from a comprehensive analysis of 16 representative particles returned from the C-type asteroid Ryugu by the Hayabusa2 mission. On average Ryugu particles consist of 50% phyllosilicate matrix, 41% porosity and 9% minor phases, including organic matter. The abundances of 70 elements from the particles are in close agreement with those of CI chondrites.
View Article and Find Full Text PDFProc Jpn Acad Ser B Phys Biol Sci
April 2019
A comprehensive geochemical study of the Chelyabinsk meteorite reveals further details regarding its history of impact-related fragmentation and melting, and later aqueous alteration, during its transit toward Earth. We support an ∼30 Ma age obtained by Ar-Ar method (Beard et al., 2014) for the impact-related melting, based on Rb-Sr isotope analyses of a melt domain.
View Article and Find Full Text PDFWe propose a simple formulation of the phase-field model for a stoichiometric compound growing in a binary liquid. In previous models, chemical free energies of stoichiometric compounds have been approximated by parabolic functions of composition; however, the curvature has been determined arbitrarily in spite of the fact that the stoichiometric composition was undesirably modified depending on the curvature. To avoid this uncertainty, we supposed that the chemical free energy of the stoichiometric compound is represented by a single value at a given temperature and derived the phase-field equations without the parabolic free-energy approximation.
View Article and Find Full Text PDFWe carry out phase field simulations to study properties of the comblike step patterns induced by an adatom source. When an adatom source advances right in front of a step, step wandering is caused by the asymmetry of the surface diffusion field and small protrusions are formed. If the velocity of the source V_{p} is smaller than a critical value V_{p}^{c}, the protrusions follow the adatom source with coarsening of the step pattern, and a regular comblike pattern with finger-like protrusions is formed.
View Article and Find Full Text PDFRev Sci Instrum
August 2015
The normal growth rates of the {110} faces of tetragonal hen egg-white lysozyme crystals, R, were measured as a function of the supersaturation σ parameter using a reflection type interferometer under μG at the International Space Station (NanoStep Project). Since water slightly evaporated from in situ observation cells during a long-term space station experiment for several months, equilibrium temperature T(e) changed, and the actual σ, however, significantly increased mainly due to the increase in salt concentration C(s). To correct σ, the actual C(s) and protein concentration C(p), which correctly represent the measured T(e) value in space, were first calculated.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
January 2015
Pattern formation of a step on a growing crystal surface induced by a straight line source of atoms, which is escaping from the step at a velocity V(p), is studied with the use of a phase field model. From a straight step, fluctuations of the most unstable wavelength λ(max) grow. Competition of intrusions leads to coarsening of the pattern, and survived intrusions grow exponentially.
View Article and Find Full Text PDFThe present study investigated the effect of nicotine exposure on gustatory plasticity in the nematode Caenorhabditis elegans. The chemotactic response of wild-type N2 nematodes pre-exposed to 100mM NaCl with 3.0mM nicotine was almost the same as that of mock-conditioned nematodes unexposed to NaCl; however, the response of N2 nematodes pre-exposed to NaCl without nicotine was significantly lower than that of mock-conditioned nematodes.
View Article and Find Full Text PDFThree-dimensional colloidal crystals made of ferromagnetic particles, such as magnetite (Fe(3)O(4)), cannot be synthesized in principle because of the strong attractive magnetic interaction. However, we discovered colloidal crystals composed of polyhedral magnetite nanocrystallites of uniform size in the range of a few hundred nanometers in the Tagish Lake meteorite. Those colloidal crystals were formed 4.
View Article and Find Full Text PDFJ Enzyme Inhib Med Chem
April 2009
Telomerase (TA) activity is known to be present in malignant tumor cells, but not in most somatic differentiated cells. TA shows relatively high activity in thyroid cancer cells, but reports vary. This fact prompted us to elucidate whether cell component inhibitors of TA in the thyroid follicles can modulate its activity.
View Article and Find Full Text PDFComputed tomography (CT)-guided thoracic sympathetic blockade with ethanol was performed while monitoring sympathetic nerve activity, with an alternating current (AC) galvanic skin reflex (GSR) monitor, in a patient with palmar hyperhidrosis in whom endoscopic thoracic sympathectomy was impossible because of pleural adhesion. Sweating was suppressed after the thoracic sympathetic blockade, and the monitor showed a significant increase in skin resistance. The effect of sympathetic blockade could be evaluated directly and in real time using a GSR monitor.
View Article and Find Full Text PDFFrom 1984 to 1999, the authors treated 64 cases of fracture of the scaphoid in children. Causes of injury were sports (n = 27), punching game machines or fighting (n = 22), and traffic accident or other trauma (n = 15). Most (46 cases) were nonunion cases.
View Article and Find Full Text PDFPlast Reconstr Surg
June 2002
The clinical results and complications of the vascularized fibular graft for the reconstruction of various long bone defects were reviewed in 60 cases. Bony reconstruction was achieved in 57 of the 60 cases; however, various postoperative complications occurred in 54 percent of the cases. One case of arterial thrombosis of an anastomosed vessel and nine cases of venous congestion of the monitoring flap occurred in the early postoperative periods.
View Article and Find Full Text PDFReplication of DNA within Saccharomyces cerevisiae chromosomes is initiated from multiple origins, whose activation follow their own inherent time schedules during the S phase of the cell cycle. It has been demonstrated that a characteristic replicative complex (RC) that includes an origin recognition complex is formed at each origin and shifts between post- and pre-replicative states during the cell cycle. We wanted to determine whether there was an association between this shift in the state of the RC and firing events at replication origins.
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