Physical Parameters of Polymer Composite Materials Created on the Basis of Low and High Molecular Weight Rubbers

ABSTRACT. The theoretical foundations of the structural and mechanical behavior of filled three-dimensional cross-linked elastomers are supplemented. Numerical experiments are carried out, based on the data of numerical experiments, three dimensional cross linked, filled with dispersed particles frost-resistant elastomers based on low and high molecular weight rubbers are developed. Theoretical and experimental data are compared and their good convergence is shown. Comparison of the physical parameters of the composites created by the authors on the basis of low and high molecular weight rubbers showed that the deformation characteristics of the composite based on high molecular weight rubbers are many times superior to composites based on low molecular weight, as well as their glass transition temperature is also very different. The created composites are recommended as a structural material in relation to the engineering problem of creating wear-resistant parts and components of road and air transport operated in a wide temperature range, including the Far North and the Arctic. &nbsp

Non-Formal Education as a Resource of Social Inclusion: Intergenerational Approach

Received 28 March 2022. Accepted 31 October 2022. Published online 30 December 2022.This article contributes to a better understanding of theoretical models and empirical evidence revealing the impact of social inclusion of non-formal education on professional and personal development in the context of five generations. Based on the typology of peculiar generations in the non-formal education market, including their interest and motivation, we have identified the differences between the benefits and the barriers to social inclusion in order to overcome social inequalities and digital inequities. Due to the fact that all generations use non-formal education, but its contribution to social inclusion differs from generation to generation, our research questions are as following: What is the impact of non-formal education on social inclusion? How do non-formal education practices differ across generations? The article critically engages with non-formal education as a resource of social inclusion highlighting the low level of inclusion of five generations. To show the specificity of five generations’ social inclusion we develop a data collection method including a questionnaire survey of the population based on the typology of generations. As such, the research shows that today inclusion through non-formal education, mobility in the labor market due to retraining, as well as inclusion in new social ties, study groups, adaptation to new challenges do have generational characteristics

Prognostic value of [18F]FDG PET radiomics to detect peritoneal and distant metastases in locally advanced gastric cancer: a side study of the prospective multicentre PLASTIC study

Aim: To improve identification of peritoneal and distant metastases in locally advanced gastric cancer using [18F]FDG-PET radiomics. Methods: [18F]FDG-PET scans of 206 patients acquired in 16 different Dutch hospitals in the prospective multicentre PLASTIC-study were analysed. Tumours were delineated and 105 radiomic features were extracted. Three classification models were developed to identify peritoneal and distant metastases (incidence: 21%): a model with clinical variables, a model with radiomic features, and a clinicoradiomic model, combining clinical variables and radiomic features. A least absolute shrinkage and selection operator (LASSO) regression classifier was trained and evaluated in a 100-times repeated random split, stratified for the presence of peritoneal and distant metastases. To exclude features with high mutual correlations, redundancy filtering of the Pearson correlation matrix was performed (r = 0.9). Model performances were expressed by the area under the receiver operating characteristic curve (AUC). In addition, subgroup analyses based on Lauren classification were performed. Results: None of the models could identify metastases with low AUCs of 0.59, 0.51, and 0.56, for the clinical, radiomic, and clinicoradiomic model, respectively. Subgroup analysis of intestinal and mixed-type tumours resulted in low AUCs of 0.67 and 0.60 for the clinical and radiomic models, and a moderate AUC of 0.71 in the clinicoradiomic model. Subgroup analysis of diffuse-type tumours did not improve the classification performance. Conclusion: Overall, [18F]FDG-PET-based radiomics did not contribute to the preoperative identification of peritoneal and distant metastases in patients with locally advanced gastric carcinoma. In intestinal and mixed-type tumours, the classification performance of the clinical model slightly improved with the addition of radiomic features, but this slight improvement does not outweigh the laborious radiomic analysis. </p

Impact of 18FFDG-PET/CT and laparoscopy in staging of locally advanced gastric cancer: a cost analysis in the prospective multicenter PLASTIC-study

BackgroundUnnecessary D2-gastrectomy and associated costs can be prevented after detecting non-curable gastric cancer, but impact of staging on treatment costs is unclear. This study determined the cost impact of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18FFDG-PET/CT) and staging laparoscopy (SL) in gastric cancer staging.Materials and MethodsIn this cost analysis, four staging strategies were modeled in a decision tree: (1) 18FFDG-PET/CT first, then SL, (2) SL only, (3) 18FFDG-PET/CT only, and (4) neither SL nor 18FFDG-PET/CT. Costs were assessed on the basis of the prospective PLASTIC-study, which evaluated adding 18FFDG-PET/CT and SL to staging advanced gastric cancer (cT3–4 and/or cN+) in 18 Dutch hospitals. The Dutch Healthcare Authority provided 18FFDG-PET/CT unit costs. SL unit costs were calculated bottom-up. Gastrectomy-associated costs were collected with hospital claim data until 30 days postoperatively. Uncertainty was assessed in a probabilistic sensitivity analysis (1000 iterations).Results18FFDG-PET/CT costs were €1104 including biopsy/cytology. Bottom-up calculations totaled €1537 per SL. D2-gastrectomy costs were €19,308. Total costs per patient were €18,137 for strategy 1, €17,079 for strategy 2, and €19,805 for strategy 3. If all patients undergo gastrectomy, total costs were €18,959 per patient (strategy 4). Performing SL only reduced costs by €1880 per patient. Adding 18FFDG-PET/CT to SL increased costs by €1058 per patient; IQR €870–1253 in the sensitivity analysis.ConclusionsFor advanced gastric cancer, performing SL resulted in substantial cost savings by reducing unnecessary gastrectomies. In contrast, routine 18FFDG-PET/CT increased costs without substantially reducing unnecessary gastrectomies, and is not recommended due to limited impact with major costs.Trial registration: NCT03208621. This trial was registered prospectively on 30-06-2017.Surgical oncolog

Evaluation of PET and laparoscopy in STagIng advanced gastric cancer:A multicenter prospective study (PLASTIC-study)

BACKGROUND: Initial staging of gastric cancer consists of computed tomography (CT) and gastroscopy. In locally advanced (cT3-4) gastric cancer, fluorodeoxyglucose positron emission tomography with CT (FDG-PET/CT or PET) and staging laparoscopy (SL) may have a role in staging, but evidence is scarce. The aim of this study is to evaluate the impact and cost-effectiveness of PET and SL in addition to initial staging in patients with locally advanced gastric cancer. METHODS: This prospective observational cohort study will include all patients with a surgically resectable, advanced gastric adenocarcinoma (cT3-4b, N0-3, M0), that are scheduled for treatment with curative intent after initial staging with gastroscopy and CT. The modalities to be investigated in this study is the addition of PET and SL. The primary outcome of this study is the proportion of patients in whom the PET or SL lead to a change in treatment strategy. Secondary outcome parameters are: diagnostic performance, morbidity and mortality, quality of life, and cost-effectiveness of these additional diagnostic modalities. The study recently started in August 2017 with a duration of 36 months. At least 239 patients need to be included in this study to demonstrate that the diagnostic modalities are break-even. Based on the annual number of gastrectomies in the participating centers, it is estimated that approximately 543 patients are included in this study. DISCUSSION: In this study, it is hypothesized that performing PET and SL for locally advanced gastric adenocarcinomas results in a change of treatment strategy in 27% of patients and an annual cost-reduction in the Netherlands of euro916.438 in this patient group by reducing futile treatment. The results of this study may be applicable to all countries with comparable treatment algorithms and health care systems. TRIAL REGISTRATION: NCT03208621 . This trial was registered prospectively on June 30, 2017

Evaluation of PET and laparoscopy in STagIng advanced gastric cancer: A multicenter prospective study (PLASTIC-study)

Background: Initial staging of gastric cancer consists of computed tomography (CT) and gastroscopy. In locally advanced (cT3-4) gastric cancer, fluorodeoxyglucose positron emission tomography with CT (FDG-PET/CT or PET) and staging laparoscopy (SL) may have a role in staging, but evidence is scarce. The aim of this study is to evaluate the impact and cost-effectiveness of PET and SL in addition to initial staging in patients with locally advanced gastric cancer. Methods: This prospective observational cohort study will include all patients with a surgically resectable, advanced gastric adenocarcinoma (cT3-4b, N0-3, M0), that are scheduled for treatment with curative intent after initial staging with gastroscopy and CT. The modalities to be investigated in this study is the addition of PET and SL. The primary outcome of this study is the proportion of patients in whom the PET or SL lead to a change in treatment strategy. Secondary outcome parameters are: diagnostic performance, morbidity and mortality, quality of life, and cost-effectiveness of these additional diagnostic modalities. The study recently started in August 2017 with a duration of 36 months. At least 239 patients need to be included in this study to demonstrate that the diagnostic modalities are break-even. Based on the annual number of gastrectomies in the participating centers, it is estimated that approximately 543 patients are included in this study. Discussion: In this study, it is hypothesized that performing PET and SL for locally advanced gastric adenocarcinomas results in a change of treatment strategy in 27% of patients and an annual cost-reduction in the Netherlands of €916.438 in this patient group by reducing futile treatment. The results of this study may be applicable to all countries with comparable treatment algorithms and health care systems

Formal Manufacturing Strategy- Does it Matter?

No abstract available

Physical Parameters of Polymer Composite Materials Created on the Basis of Low and High Molecular Weight Rubbers

The objective of this work is the further development theoretical foundations of structural and mechanical behavior of the filled three-dimensionally cross-linked elastomers. The use of mathematical modeling it was possible to create three-dimensionally cross-linked, filled with dispersed particles, frost-resistant elastomers based on low and high molecular weight rubbers at the minimal cost. Theoretical and experimental data are compared and their good convergence is shown. A comparison of the physical parameters of the composites showed that the deformation characteristics of the composite based on high molecular rubbers are many times higher than composites based on low molecular weight rubbers, and also their glass transition temperatures differ sharply. The created composites are recommended as a structural material in relation to the engineering problem of creating wear-resistant parts and components of automobile and aviation vehicles operating in a wide temperature range, including in the Far North and the Arcti

Non-Formal Education as a Resource of Social Inclusion: Intergenerational Approach

This article contributes to a better understanding of theoretical models and empirical evidence revealing the impact of social inclusion of non-formal education on professional and personal development in the context of five generations. Based on the typology of peculiar generations in the non-formal education market, including their interest and motivation, we have identified the differences between the benefits and the barriers to social inclusion in order to overcome social inequalities and digital inequities. Due to the fact that all generations use non-formal education, but its contribution to social inclusion differs from generation to generation, our research questions are as following: What is the impact of non-formal education on social inclusion? How do non-formal education practices differ across generations? The article critically engages with non-formal education as a resource of social inclusion highlighting the low level of inclusion of five generations. To show the specificity of five generations’ social inclusion we develop a data collection method including a questionnaire survey of the population based on the typology of generations. As such, the research shows that today inclusion through non-formal education, mobility in the labor market due to retraining, as well as inclusion in new social ties, study groups, adaptation to new challenges do have generational characteristics.</jats:p