90 research outputs found
A comparison of nephrotoxicity between patients with a solitary-functioning kidney and those with bilateral-functioning kidneys in cisplatin-based chemotherapy for advanced urothelial carcinoma: a Japanese retrospective multi-institutional study
BackgroundTo compare the prevalence of nephrotoxicity between patients with a solitary-functioning kidney versus those with bilateral-functioning kidneys during the administration of cisplatin-based chemotherapy for advanced urothelial carcinoma.MethodsWe retrospectively analyzed 244 advanced urothelial carcinoma patients treated with cisplatin-based chemotherapy between 2004 and 2010 at 17 institutes in Japan. The 24 h creatinine clearance, Cockcroft–Gault formula, and estimated glomerular filtration rate equation (eGFR), were compared before all chemotherapies. The urinary tract function status was determined based on the data of nephroureterectomy, hydronephrosis, and relief of upper urinary tract obstruction. A total of 244 patients were divided into four groups according to their urinary tract functioning status and eGFR results, including bilateral-functioning kidneys with pretreatment eGFR ≥60 mL/min/1.73 m2 group (n = 83, 34.0%); a solitary-functioning kidney with pretreatment eGFR ≥60 mL/min/1.73 m2 group (n = 36, 14.8%); bilateral-functioning kidneys with pretreatment eGFR 10% and 30% from baseline in the post-third-course of chemotherapy was significantly higher in patients with bilateral-functioning kidneys than in those with a solitary-functioning kidney, among patients with pretreatment eGFR 20% from baseline were significantly higher in patients with bilateral-functioning kidneys than those with a solitary-functioning kidney among patients with pretreatment eGFR < 60 mL/min/1.73 m2 (p = 0.034), whereas no significant difference was observed among patients with pretreatment eGFR ≥60 mL/min/1.73 m2.ConclusionsThe results suggest that cisplatin-based chemotherapy may have more nephrotoxicity in patients with bilateral-functioning kidneys than in those with a solitary-functioning kidney
Controlled rejuvenation of amorphous metals with thermal processing
Rejuvenation is the configurational excitation of amorphous materials and is one of the more promising approaches for improving the deformability of amorphous metals that usually exhibit macroscopic brittle fracture modes. Here, we propose a method to control the level of rejuvenation through systematic thermal processing and clarify the crucial feasibility conditions by means of molecular dynamics simulations of annealing and quenching. We also experimentally demonstrate rejuvenation level control in Zr55Al10Ni55Cu30 bulk metallic glass. Our local heat-treatment recipe (rising temperature above 1.1TG, followed by a temperature quench rate exceeding the previous) opens avenue to modifying the glass properties after it has been cast and processed into near component shape, where a higher local cooling rate may be afforded by for example transient laser heating, adding spatial control and great flexibility to the processing
Atomistic study of liquid fragility and spatial heterogeneity of glassy solids in model binary alloys
Abstract Fragility is a fundamental property of glass-forming liquids. Here, we evaluated the liquid fragility and structural and dynamic heterogeneity of glassy solids for four model binary alloys. The most fragile alloy exhibited the maximum dynamic heterogeneity in the mechanical unfreezing process. The local atomic order contributed to structural and dynamic heterogeneities in the glassy solid. We observed that atomic displacement significantly correlated with degrees of clustering of local atomic orders. The clustering produced during the glass-forming quenching process enhanced structural and dynamic heterogeneities, especially in fragile glass alloys. Therefore, this alloy system exhibited correlations among liquid fragility, dynamic heterogeneity in liquid alloys, and dynamic and structural heterogeneities in glassy solids. We discussed the underlying physics of the correlation based on a theoretical model for fragility. These structural and dynamic analyses also provided deeper insights into the features of structural heterogeneity in glassy solids. The alloy with the most fragility exhibited the largest difference in atomic mobility between the densely and loosely packed local atomic orders, implying the greatest heterogeneity in the degree of packing density
Effects of Atomic Deviatoric Distortion on Local Glass Transition of Metallic Glasses
The dependence of the glass transition on the local volumetric strain of each atom has been shown by Egami and others. The atomistic strain defined by the deformation tensor of the Voronoi polyhedra exhibits a different tendency from that of the total strain of the whole system. Even below the glass transition temperature, some percent of the atoms have strains that are already over the critical strain predicted by theory. In addition, the atomic deviatoric distortion has a non-zero value, while the total deviatoric distortion remains zero at the glass transition in the heat cycle. In this paper, the strain states at the glass transition, such as the volumetric strain and deviatoric distortion, are investigated for Cu and Zr based amorphous metals with three different compositions. We found that the local glass transition depends on the deviatoric distortion of atoms and, in these cases, starts at 600K, a lower temperature, than that of the global glass transition at 1100K
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