著者

Ozawa Misaki Kuroiwa Takeshi Ikeda Atsushi Miyazaki Kunimasa

出版者

American Physical Society

雑誌

Physical review letters (ISSN:00319007)

巻号頁・発行日

vol.109, no.20, pp.205701, 2012-11

被引用文献数

56 6

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Recent studies show that volume fractions φJ at the jamming transition of frictionless hard spheres and disks are not uniquely determined but exist over a continuous range. Motivated by this observation, we numerically investigate the dependence of φJ on the initial configurations of the parent fluid equilibrated at a volume fraction φeq, before compressing to generate a jammed packing. We find that φJ remains constant when φeq is small but sharply increases as φeq exceeds the dynamic transition point which the mode-coupling theory predicts. We carefully analyze configurational properties of both jammed packings and parent fluids and find that, while all jammed packings remain isostatic, the increase of φJ is accompanied with subtle but distinct changes of local orders, a static length scale, and an exponent of the finite-size scaling. These results are consistent with the scenario of the random first-order transition theory of the glass transition.

著者

Ikeda Atsushi Kawai Koji Ando Satoshi Oikawa Takehiro Inai Hiromu Kimura Tomokazu Takaoka Ei-ichiro Yoshino Takayuki Suetomi Takahiro Kojima Takahiro Miyazaki Jun Nishiyama Hiroyuki

出版者

Oxford University Press.

雑誌

Japanese journal of clinical oncology (ISSN:03682811)

巻号頁・発行日

vol.42, no.8, pp.748-752, 2012-08

被引用文献数

8

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OBJECTIVE:Ureteral obstruction is one of the complications of testicular tumor with retroperitoneal lymph node metastasis that requires ureteral stenting for management. We elucidated the clinical courses of ureteral obstructions and changes in renal functions in patients with indwelling ureteral stenting.METHODS:The medical records of 56 patients who were treated for metastatic testicular tumors by chemotherapy at a single institute between 2002 and 2010 were retrospectively reviewed.RESULTS:Among 56 patients, 12 patients needed ureteral stenting before chemotherapy. The proportion of patients requiring ureteral stenting was significantly higher in seminoma than non-seminoma (47 and 12%, respectively, P < 0.05). The ureteral stent was removed after chemotherapy or retroperitoneal lymph node dissection in all patients, except for one patient who died of cancer during chemotherapy. At retroperitoneal lymph node dissection, ureters were spared in three patients, a partial ureterectomy was needed in one patient, and no case underwent adjunctive nephrectomy. These 11 patients presented no local and distant recurrence at median follow-up of 44 months. Ureteral stenting increased the estimated glomerular filtration rate to more than 60 ml/min before chemotherapy in all patients, but it decreased to <60 ml/min in 6 of 11 patients after chemotherapy.CONCLUSIONS:Ureteral obstruction due to testicular tumor was relieved after chemotherapy or retroperitoneal lymph node dissection. Ureteral stenting was effective to improve renal function before chemotherapy, although we should pay special attention to deterioration of renal function during or after chemotherapy.

著者

Ikeda Atsushi Miyazaki Kunimasa

出版者

American Institute of Physics

雑誌

The journal of chemical physics (ISSN:00219606)

巻号頁・発行日

vol.135, no.2, pp.024901, 2011

被引用文献数

15

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We numerically study thermodynamic and structural properties of the one-component Gaussian core model at very high densities. The solid-fluid phase boundary is carefully determined. We find that the density dependence of both the freezing and melting temperatures obey the asymptotic relation, log Tf, log Tm∝ − ρ2/3, where ρ is the number density, which is consistent with Stillinger's conjecture. Thermodynamic quantities such as the energy and pressure and the structural functions such as the static structure factor are also investigated in the fluid phase for a wide range of temperature above the phase boundary. We compare the numerical results with the prediction of the liquid theory with the random phase approximation (RPA). At high temperatures, the results are in almost perfect agreement with RPA for a wide range of density, as it has already been shown in the previous studies. In the low temperature regime close to the phase boundary line, although RPA fails to describe the structure factors and the radial distribution functions at the length scales of the interparticle distance, it successfully predicts their behaviors at longer length scales. RPA also predicts thermodynamic quantities such as the energy, pressure, and the temperature at which the thermal expansion coefficient becomes negative, almost perfectly. Striking ability of RPA to predict thermodynamic quantities even at high densities and low temperatures is understood in terms of the decoupling of the length scales which dictate thermodynamic quantities from the interparticle distance which dominates the peak structures of the static structure factor due to the softness of the Gaussian core potential.

著者

Ikeda Atsushi Miyazaki Kunimasa

出版者

American Institute of Physics

雑誌

The journal of chemical physics (ISSN:00219606)

巻号頁・発行日

vol.135, no.5, pp.054901, 2011

被引用文献数

27 8

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We numerically study crystal nucleation and glassy slow dynamics of the one-component Gaussian core model (GCM) at high densities. The nucleation rate at a fixed supercooling is found to decrease as the density increases. At very high densities, the nucleation is not observed at all in the time window accessed by long molecular dynamics (MD) simulation. Concomitantly, the system exhibits typical slow dynamics of the supercooled fluids near the glass transition point. We compare the simulation results of the supercooled GCM with the predictions of mode-coupling theory (MCT) and find that the agreement between them is better than any other model glassformers studied numerically in the past. Furthermore, we find that a violation of the Stokes-Einstein relation is weaker and the non-Gaussian parameter is smaller than canonical glassformers. Analysis of the probability distribution of the particle displacement clearly reveals that the hopping effect is strongly suppressed in the high density GCM. We conclude from these observations that the GCM is more amenable to the mean-field picture of the glass transition than other models. This is attributed to the long-ranged nature of the interaction potential of the GCM in the high density regime. Finally, the intermediate scattering function at small wavevectors is found to decay much faster than its self part, indicating that dynamics of the large-scale density fluctuations decouples with the shorter-ranged caging motion.

著者

Ikeda Atsushi Miyazaki Kunimasa

出版者

American Institute of Physics

雑誌

The journal of chemical physics (ISSN:00219606)

巻号頁・発行日

vol.135, no.2, pp.024901, 2011-07

被引用文献数

15 16

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We numerically study thermodynamic and structural properties of the one-component Gaussian core model at very high densities. The solid-fluid phase boundary is carefully determined. We find that the density dependence of both the freezing and melting temperatures obey the asymptotic relation, log Tf, log Tm∝ − ρ2/3, where ρ is the number density, which is consistent with Stillinger's conjecture. Thermodynamic quantities such as the energy and pressure and the structural functions such as the static structure factor are also investigated in the fluid phase for a wide range of temperature above the phase boundary. We compare the numerical results with the prediction of the liquid theory with the random phase approximation (RPA). At high temperatures, the results are in almost perfect agreement with RPA for a wide range of density, as it has already been shown in the previous studies. In the low temperature regime close to the phase boundary line, although RPA fails to describe the structure factors and the radial distribution functions at the length scales of the interparticle distance, it successfully predicts their behaviors at longer length scales. RPA also predicts thermodynamic quantities such as the energy, pressure, and the temperature at which the thermal expansion coefficient becomes negative, almost perfectly. Striking ability of RPA to predict thermodynamic quantities even at high densities and low temperatures is understood in terms of the decoupling of the length scales which dictate thermodynamic quantities from the interparticle distance which dominates the peak structures of the static structure factor due to the softness of the Gaussian core potential.