Comparison of nanoparticle diameter measurements by Atomic Force Microscopy and Scanning Electron Microscopy

Using combined AFM ( Atomic Force Microscope) and a SEM (Scanning Electron Microscope) makes it possible to accurately measure a nano-object in 3 dimensions. This paper deals with the traceable measurements of the size and the size distribution of a SiO2 spherical shaped nanoparticle population performed by both microscopy techniques. The complementary nature of AFM and SEM is investigated. The construction of size distribution histogram was carried out by means of a homemade program described here. This semi-automatic program is capable of counting only isolated nanoparticles and eliminating measurement artefacts and aggregates. Finally, a comparison between both measurement types is proposed

Isolated lymph node recurrence in epithelial ovarian cancer: recurrence with better prognosis?

International audienceIntroduction The aim of this study was to compare overall survival (OS) between women with isolated lymph node recurrence (ILNR) and those with isolated peritoneal localization of recurrence (ICR), in patients managed for epithelial ovarian cancer.Methods Data from 1508 patients with ovarian cancer were collected retrospectively from1 January 2000 to 31 December 2016, from the FRANCOGYN database, pooling data from 11 centres specialized in ovary treatment. Median overall survival was determined using the Kaplan-Meier method. Univariate and multivariate analyses were performed to define prognostic factors of overall survival. Patients included had a first recurrence defined as ILNR or ICR during their follow up.Results 79 patients (5.2 %) presented with ILNR, and 247 (16.4 %) patients had isolated carcinomatosis recurrence. Complete lymphadenectomy was performed more frequently in the ILNR group vs. the ICR group (67.1 % vs. 53.4 %, p = 0.004) and the number of pelvic lymph nodes involved was higher (2.4 vs. 1.1, p = 0.008). The number of involved pelvic LN was an independent predictor of ILNR (OR = 1.231, 95 % CI [1.074–1.412], p = 0.0024). The 3-year and 5-year OS rates in the ILNR group were 85.2 % and 53.7 % respectively, compared to 68.1 % and 46.8 % in patients with ICR. There was no significant difference in terms of OS after initial diagnosis (p = 0.18). 3- year and 5-year OS rates after diagnosis of recurrence were 62.6 % and 15.6 % in the ILNR group, and 44 % and 15.7 % in patients with ICR (p = 0.21).Conclusion ILNR does not seem to be associated with a better prognosis in terms of OS

Thickness measurements of graphene oxide flakes using atomic force microscopy:Results of an international interlaboratory comparison

Flake thickness is one of the defining properties of graphene-related 2D materials (GR2Ms), and therefore requires reliable, accurate, and reproducible measurements with well-understood uncertainties. This is needed regardless of the production method or manufacturer because it is important for all GR2M products to be globally comparable. An international interlaboratory comparison on thickness measurements of graphene oxide (GO) flakes using atomic force microscopy (AFM) has been completed in Technical Working Area 41 of Versailles Project on Advanced Materials and Standards (VAMAS). Twelve laboratories participated in the comparison project, led by NIM, China, to improve the equivalence of thickness measurement for two-dimensional flakes. The measurement methods, uncertainty evaluation and a comparison of the results and analysis are reported in this manuscript. The data and results of this project will be directly used to support the development of an ISO standard