Comparison of a Material Point Method and a Galerkin Meshfree Method for the Simulation of Cohesive-Frictional Materials

The simulation of large deformation problems, involving complex history-dependent constitutive laws, is of paramount importance in several engineering fields. Particular attention has to be paid to the choice of a suitable numerical technique such that reliable results can be obtained. In this paper, a Material Point Method (MPM) and a Galerkin Meshfree Method (GMM) are presented and verified against classical benchmarks in solid mechanics. The aim is to demonstrate the good behavior of the methods in the simulation of cohesive-frictional materials, both in static and dynamic regimes and in problems dealing with large deformations. The vast majority of MPM techniques in the literatrue are based on some sort of explicit time integration. The techniques proposed in the current work, on the contrary, are based on implicit approaches, which can also be easily adapted to the simulation of static cases. The two methods are presented so as to highlight the similarities to rather than the differences from "standard" Updated Lagrangian (UL) approaches commonly employed by the Finite Elements (FE) community. Although both methods are able to give a good prediction, it is observed that, under very large deformation of the medium, GMM lacks robustness due to its meshfree natrue, which makes the definition of the meshless shape functions more difficult and expensive than in MPM. On the other hand, the mesh-based MPM is demonstrated to be more robust and reliable for extremely large deformation cases

How to communicate with families living in complete isolation

The global emergency caused by the SARS-CoV-2 pandemic has suddenly changed how we communicate with families in all the CoViD19 care settings, on account of the need to maintain complete social isolation. Far-reaching mental suffering manifests itself in widespread anxiety. Health workers are isolated from their families, and must manage the consequences of this isolation just like the patients under their care. Patients and their families perceive not only the clinical results but also the personal attitudes, closeness and psychological support from the care teams. This perception of genuine participation by the health worker in the course of the treatment is especially important when a patient dies, and may influence the whole process of grief

Practice patterns and 90-day treatment-related morbidity in early-stage cervical cancer

To evaluate the impact of the Laparoscopic Approach to Cervical Cancer (LACC) Trial on patterns of care and surgery-related morbidity in early-stage cervical cancer

Evaluating long-term outcomes of three approaches to retroperitoneal staging in endometrial cancer.

OBJECTIVE Sentinel lymph node mapping (SNM) has gained popularity in managing apparent early-stage endometrial cancer (EC). Here, we evaluated the long-term survival of three different approaches of nodal assessment. METHODS This is a multi-institutional retrospective study evaluating long-term outcomes of EC patients having nodal assessment between 01/01/2006 and 12/31/2016. In order to reduce possible confounding factors, we applied a propensity-matched algorithm. RESULTS Overall, 940 patients meeting inclusion criteria were included in the study, of which 174 (18.5%), 187 (19.9%), and 579 (61.6%) underwent SNM, SNM followed by backup lymphadenectomy (LND) and LND alone, respectively. Applying a propensity score matching algorithm (1:1:2) we selected 500 patients, including 125 SNM, 125 SNM/backup LND, and 250 LND. Baseline characteristics of the study population were similar between groups. The prevalence of nodal disease was 14%, 16%, and 12% in patients having SNM, SNM/backup LND and LND, respectively. Overall, 19 (7.6%) patients were diagnosed with low volume nodal disease. The survival analysis comparing the three techniques did not show statistical differences in terms of disease-free (p = 0.750) and overall survival (p = 0.899). Similarly, the type of nodal assessment did not impact survival outcomes after stratification based on uterine risk factors. CONCLUSION Our study highlighted that SNM provides similar long-term oncologic outcomes than LND

Outcomes of High-Grade Cervical Dysplasia with Positive Margins and HPV Persistence after Cervical Conization

The objective of this work is to assess the 5-year outcomes of patients undergoing conization for high-grade cervical lesions that simultaneously present as risk factors in the persistence of HPV infection and the positivity of surgical resection margins. This is a retrospective study evaluating patients undergoing conization for high-grade cervical lesions. All patients included had both positive surgical margins and experienced HPV persistence at 6 months. Associations were evaluated with Cox proportional hazard regression and summarized using hazard ratio (HR). The charts of 2966 patients undergoing conization were reviewed. Among the whole population, 163 (5.5%) patients met the inclusion criteria, being at high risk due to the presence of positive surgical margins and experiencing HPV persistence. Of 163 patients included, 17 (10.4%) patients developed a CIN2+ recurrence during the 5-year follow-up. Via univariate analyses, diagnosis of CIN3 instead of CIN2 (HR: 4.88 (95%CI: 1.10, 12.41); p = 0.035) and positive endocervical instead of ectocervical margins (HR: 6.44 (95%CI: 2.80, 9.65); p < 0.001) were associated with increased risk of persistence/recurrence. Via multivariate analyses, only positive endocervical instead of ectocervical margins (HR: 4.56 (95%CI: 1.23, 7.95); p = 0.021) were associated with worse outcomes. In this high-risk group, positive endocervical margins is the main risk factor predicting 5-year recurrence