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Refining Patient Selection for Reirradiation of Head and Neck Squamous Carcinoma in the IMRT Era: A Multi-institution Cohort Study by the MIRI Collaborative
The therapeutic ratio of reirradiation for recurrent or second primary (RSP) squamous carcinoma of the head and neck may be improved in the intensity modulated radiation therapy (IMRT) era. However, patient selection for reirradiation remains challenging. We performed a multi-institution cohort study to investigate modern outcomes after IMRT-based reirradiation and to identify prognostic subgroups.
Radiomic Biomarkers to Refine Risk Models for Distant Metastasis in HPV-related Oropharyngeal Carcinoma
Distant metastasis (DM) is the main cause of death for patients with human papillomavirus (HPV)–related oropharyngeal cancers (OPCs); yet, there are few reliable predictors of DM in this disease. The role of quantitative imaging (ie, radiomic) analysis was examined to determine whether there are primary tumor features discernible on imaging studies that are associated with a higher risk of DM developing.
Risk of Late Urinary Complications Following Image Guided Adaptive Brachytherapy for Locally Advanced Cervical Cancer: Refining Bladder Dose-Volume Parameters
To study correlations between dose-volume parameters of the whole bladder and bladder trigone and late urinary toxicity in locally advanced cervical cancer patients treated with pulsed-dose-rate brachytherapy.
Mesh refinement schemes for the concurrent atomistic-continuum method
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Grain refining and mechanical properties of AZ31 alloy processed by accumulated extrusion bonding
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Quantifying accessible sites and reactivity on titania–silica (photo)catalysts: Refining TOF calculations
It can be difficult to determine the number of active atoms accessible to the fluid phase in mixed oxide catalysts, as required for obtaining true turnover frequencies (TOF). Here, we utilize the selective titration of surface Ti atoms with phenylphosphonic acid (PPA) on TiO 2 –SiO 2 materials to estimate the number of reactant-accessible sites. TiO 2 –SiO 2 composites were synthesized over a range of Ti loadings from grafting of titanocene dichloride (Cp 2 TiCl 2 ) or tetraethoxy orthotitanate (TEOT) on SiO 2 and sol–gel co-hydrolysis of Si and Ti alkoxides. The materials were characterized by DRUV–vis, XRD, BET, and XANES. Despite the significant morphological and electronic differences, materials prepared by Cp 2 TiCl 2 and TEOT yielded a near-constant TOF of 0.14 h -1 (±0.04) across Ti loadings, for benzyl alcohol photooxidation, when normalizing rates by sites titrated by PPA. The fraction of Ti atoms titrated by PPA was strongly dependent on synthesis method and surface density. PPA titration and benzyl alcohol photooxidation may be useful measures of surface accessibility in other supported oxides.
3D level set methods for evolving fronts on tetrahedral meshes with adaptive mesh refinement
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Massively parallel finite difference elasticity using block-structured adaptive mesh refinement with a geometric multigrid solver
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The U.S. crude oil refining industry: Recent developments, upcoming challenges and prospects for exports
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Magnetic and mechanical properties of grain-refined Dy-free Nd-Fe-B sintered magnets
In this work, the effects of grain size on magnetic and mechanical properties of Dy-free Nd-Fe-B sintered magnets were studied. The grain size of the sintered magnets was varied by using different sized Dy-free Nd-Fe-B alloy feedstock powders which were ball milled to different extents. Increasing the ball milling time from 7 to 11 h caused the average particle size of the powders to decrease from 3.6 to 2.1 µm, while the average grain size of the corresponding sintered magnets decreased from 5.0 to 4.0 µm. The intrinsic coercivity Hcj and maximum energy product (BH) max of these magnets increased from 11.6 to 13.7 kOe and 41.6 to 43.6 MGOe, respectively. The finer grain magnets exhibited better thermal stability, as indicated by a smaller temperature coefficient of H cj (-0.71%/°C). With extending ball milling time to 15 h, the magnetic properties of the magnets deteriorate, while the flexural strengths first decrease and then increase. The flexural strength improvement is attributed to the increased Oxygen content in the magnets due to finer grains. The coercivity enhancement by reduction of grain size is a promising approach to develop Dy-free Nd-Fe-B sintered magnets with better thermal stability. It is important to control the Oxygen contents in the magnets to compromise both magnetic and mechanical properties.
Crystal structure of Ba{sub 2}InTaO{sub 6} as determined by the Rietveld refinement
Rietveld profile analysis of X-ray diffraction data was carried out to determine the symmetry and crystal structures of the double perovskite Ba{sub 2}InTaO{sub 6}. Contrary to a recent study of Raman spectroscopy, we find no evidence that Ba{sub 2}InTaO{sub 6} adopts the tetragonal space group P4/mnc of the tilt system a{sup 0}a{sup 0}c{sup +}. Instead, it has cubic symmetry with the space group Fm3-bar m in the temperature range 82-723 K. In Ba{sub 2}InTaO{sub 6} the ordering between In(III) and Ta(V) cations is a difficult process requiring prolonged heat treatment at high temperature. -- Graphical abstract: Enlarged sections of the X-ray diffraction pattern of Ba{sub 2}InTaO{sub 6} showing the basic (222) and (400) reflections. Insert shows the evolution of these reflections as function of temperature. No peak splitting is observed in the temperature range between 82 and 723 K. Display Omitted Research highlights: {yields} The ordering between In(III) and Ta(V) cations in Ba{sub 2}InTaO{sub 6} is controlled by kinetic process requiring prolonged heat treatment. {yields} Ba{sub 2}InTaO{sub 6} adopts the cubic space group Fm3-bar m instead of tetragonal P4/mnc. {yields} No phase transition occurs in the temperature range between 82 and 723 K.
Crystal structure of Sr{sub 6}Y{sub 2}Al{sub 4}O{sub 15}: XRD refinements and first-principle calculations
The ternary oxide phase Sr{sub 6}Y{sub 2}Al{sub 4}O{sub 15} (SYA) was synthesized and the crystal structure was determined by using the X-ray powder diffraction data. Structure of the phase can be considered as an oxygen-deficient perovskite Sr(Y{sub 1/3}Al{sub 2/3})O{sub 2.5} and has a monoclinic C2 (S.G. No. 5) unit cell with the unit cell parameters: a=17.597(1) A, b=5.7408(1) A, c=7.6860(1) A, {beta}=90.7659(3) Degree-Sign , V{sub cell}=776.37(1) A{sup 3}, Z=2. By bond parameter analysis and first-principle calculations, we confirmed the reasonability of our crystal structure model. According to the calculated band structure, SYA has an indirect band gap {approx}4.3 eV and a direct band gap {approx}4.4 eV, which is wide to be transparent to UV and visible lights. We also synthesized other rare-earth isomorphs Sr{sub 6}Ln{sub 2}Al{sub 4}O{sub 15} (Ln=Tb, Dy, Ho, Er, Tm, Yb and Lu) and obtained their cell parameters. - Graphical abstract: Sr{sub 6}Y{sub 2}Al{sub 4}O{sub 15} has a monoclinic unit cell with space group C2 (5) with unit cell parameters: a=17.597(1) A, b=5.7408(1) A, c=7.6860(1) A, {beta}=90.7659(3) Degree-Sign . Highlights: Black-Right-Pointing-Pointer Sr{sub 6}Y{sub 2}Al{sub 4}O{sub 15} (SYA) has an oxygen-deficient perovskite structure Sr(Y{sub 1/3}Al{sub 2/3})O{sub 2.5}. Black-Right-Pointing-Pointer SYA shows C2 symmetry: a=17.597(1) A, b=5.7408(1) A, c=7.6860(1) A, {beta}=90.7659(3) Degree-Sign . Black-Right-Pointing-Pointer SYA has an indirect band gap {approx}4.3 eV and a direct band gap {approx}4.4 eV.
Structure refinements of members in the brownmillerite solid solution series Ca{sub 2}Al{sub x}(Fe{sub 0.5}Mn{sub 0.5}){sub 2-x}O{sub 5+{delta}} with 1/2{<=}x{<=}4/3
Four different brownmillerite solid solutions Ca{sub 2}Al{sub x}(Fe{sub 0.5}Mn{sub 0.5}){sub 2-x}O{sub 5+{delta}} with 1/2{<=}x{<=}4/3 were synthesized by a solid oxide ceramic method. The phases crystallize either in a primitive centered orthorhombic cell with space group Pnma or in a body centered cell with space group I2mb dependent on the aluminum concentration present in the solid solution. Mn{sup 3+} ions occupy exclusively site 4a coordinated by six oxygen anions. Increasing Mn{sup 3+} concentrations cause a remarkable distortion of the octahedron and indirectly of the tetrahedron, resulting in twisted and tilted octahedral layers as well as buckled tetrahedral chains. The influences are discussed on the site 4a of trivalent manganese due to its Jahn-Teller activity, with regard to the occupation of octahedron and tetrahedron with different sized iron and aluminum ions. - Graphical Abstract: The coupled substitution Fe{sup 3+}>Mn{sup 3+}+Fe{sup 3+} <=>2 Al{sup 3+} in brownmillerite phases (Ca{sub 2}(Fe{sub 0.5}Mn{sub 0.5}){sub 2-x}Al{sub x}O{sub 5+{delta}}) changes predominantly their structural properties, which is essential for the hydration performance of the calcium aluminate cement, where brownmillerites occur as clinker phases. Highlights: Black-Right-Pointing-Pointer We present structural data of four Ca-Al-Fe-Mn-brownmillerites. Black-Right-Pointing-Pointer Mn{sup 3+}-ions occupy exclusively the octahedrally coordinated site 0,0,0. Black-Right-Pointing-Pointer Bonds and angles of the octahedrally coordinated site are distorted strongly. Black-Right-Pointing-Pointer Mn{sup 3+}-ions influence indirectly the shape of the tetrahedron. Black-Right-Pointing-Pointer Mn{sup 3+}-ions stabilize Pnma instead of I2mb in Ca-Al-Fe-Mn-brownmillerites.