Dosimetry and plan parameters study of three-dimensional-printed template-based intra-cavitary/interstitial interpolation technology using computed tomography-guided high-dose-rate brachytherapy in locally advanced cervical cancer.

Purpose: To explore differences in dosimetry and planning parameters between intra-cavitary/interstitial interpolation (IC + ISBT) three-dimensional (3D)-printed template-based (3D-printed) and simple intra-cavity (ICBT) radiation techniques using a fixed Rotterdam three-tube applicator (TT) for computed tomography-guided high-dose-rate brachytherapy in locally advanced cervical cancer. Material and methods: This retrospective study included 100 patients (n = 50 each in 3D-printed and Rotterdam three-tube applicator treatment groups) with FIGO stages IIB-IVB cervical cancer from May 2019 to May 2022. Using high-risk clinical target volume, 377 of 400 plans categorized at intervals of 10 cm3 into 20-30, 30-40, 40-50, 50-60, 60-70, and 70-80 cm3; 23 plans with < 20 and > 80 cm3 volume were excluded. Dosimetry parameters (D90 and D98 of high-risk clinical target volume, and D2cc of organs at risk, including bladder, rectum, sigmoid, and bowel) and planning parameters (homogeneity index [HI], conformation number [CN], and organ at risk sparing factor) were compared between the two groups separately for six high-risk clinical target volume plan categories. Results: For the 3D-printing group, target coverage, organs at risk protection, and plan conformity and uniformity were better than those for the Rotterdam three-tube group. Particularly, in high-risk clinical target volume plans between 50-60 cm3, the mean D90 and D98 of high-risk clinical target volume were approximately 0.35 and 0.3 Gy higher, while the average D2cc of the bladder, rectum, sigmoid, and bowel were approximately 1.3, 0.9, 0.9, and 0.8 Gy significantly lower than those of the Rotterdam three-tube group, respectively (p < 0.05). The above-mentioned planning parameters differed significantly between the groups (p < 0.05). Conclusions: For the 3D-printing group, IC/ISBT reduced the dose for organs at risk while ensuring target coverage and conformation. This was especially noticeable for plans with high-risk clinical target volume of 50-60 cm3.

The Effect of Ni Interlayer on the Hot-Rolled and Quenched Stainless Steel Clad Plate.

The vacuum hot-rolled SUS314/Q235 stainless steel clad plate has many drawbacks including serious interface alloy element diffusion, stainless steel cladding's sensitization, and carbon steel substrate's low strength. In this study, the comprehensive properties were systematically adjusted by changing the thickness of the Ni interlayer (0, 100, 200 µm) and the quenching temperature (1000~1150 °C). The results showed that the Ni interlayer can obviously hinder the diffusion of carbon element, so as to achieve the purpose of eliminating the decarburized layer and reducing the carbon content of the carburized layer. Meanwhile, the perfect metallurgical bonding between the substrate and cladding can be obtained, effectively improving the stainless steel clad plate's tensile shear strength and comprehensive mechanical properties, and significantly reduce the brittleness of the carburized layer. As the quenching temperature increases, the grains coarsening of carbon steel and stainless steel became more and more serious, and the sensitization phenomenon and the thickness of the carburized layer are gradually decreased. The stainless steel clad plate (Ni layer thickness of 100 µm) quenched at 1050 °C had the best comprehensive mechanical properties. Herein, the interface shear strength, tensile strength and the fracture elongation reached 360.5 MPa, 867 MPa and 16.10%, respectively, achieving strengthening and toughening aim. This is attributed to the disappearance of the sensitization phenomenon, the grain refinement and the lower interface residual stress.

Facile Synthesis of SiO2@C Nanoparticles Anchored on MWNT as High-Performance Anode Materials for Li-ion Batteries.

Carbon-coated silica nanoparticles anchored on multi-walled carbon nanotubes (SiO2@C/MWNT composite) were synthesized via a simple and facile sol-gel method followed by heat treatment. Scanning and transmission electron microscopy (SEM and TEM) studies confirmed densely anchoring the carbon-coated SiO2 nanoparticles onto a flexible MWNT conductive network, which facilitated fast electron and lithium-ion transport and improved structural stability of the composite. As prepared, ternary composite anode showed superior cyclability and rate capability compared to a carbon-coated silica counterpart without MWNT (SiO2@C). The SiO2@C/MWNT composite exhibited a high reversible discharge capacity of 744 mAh g-1 at the second discharge cycle conducted at a current density of 100 mA g-1 as well as an excellent rate capability, delivering a capacity of 475 mAh g-1 even at 1000 mA g-1. This enhanced electrochemical performance of SiO2@C/MWNT ternary composite anode was associated with its unique core-shell and networking structure and a strong mutual synergistic effect among the individual components.