Asymmetric Elastoplastic Behavior and Failure of GEM Foils

The nonlinear isotropic power hardening and the cohesive zone material (CZM) [1] criteria are applied in ANSYS [2] finite element simulations to analyze very large deformations of the GEM foils up to the failure in uniaxial tensile tests. Some data available in literature concerning both the PI/Cu and the grain boundary interfaces are utilized. The computed progressive plasticization of the perforated thin multilayer agree very well with the experimental results published by some researchers [3–6]. However the present work provides a different explanation of that behavior (already suggested in an earlier note of the author [7]) and it should be considered as a critical review concerning the conclusions of the aforementioned works

Fiber Bragg Grating sensors for deformation monitoring of GEM foils in HEP detectors

Fiber Bragg Grating (FBG) sensors have been so far mainly used in high energy physics (HEP) as high precision positioning and re-positioning sensors and as low cost, easy to mount, radiation hard and low space- consuming temperature and humidity devices. FBGs are also commonly used for very precise strain measurements. In this work we present a novel use of FBGs as flatness and mechanical tensioning sensors applied to the wide Gas Electron Multiplier (GEM) foils of the GE1/1 chambers of the Compact Muon Solenoid (CMS) experiment at Large Hadron Collider (LHC) of CERN. A network of FBG sensors has been used to determine the optimal mechanical tension applied and to characterize the mechanical stress applied to the foils. The preliminary results of the test performed on a full size GE1/1 final prototype and possible future developments will be discussed.Comment: Four pages, seven figures. Presented by Michele Caponero at IWASI 2015, Gallipoli (Italy

PTEN as a predictive marker of response to conservative treatment in endometrial hyperplasia and early endometrial cancer. A systematic review and meta-analysis

OBJECTIVE: Several markers have been studied to predict the responsiveness of endometrial hyperplasia (EH) and early endometrial cancer (EEC) to progestin therapy. PTEN has played a major role in this field, although its predictive significance is still undefined. We aimed to assess if loss of PTEN expression on pre-treatment endometrial specimen may be a predictive markers of response to progestins in EH and EEC. STUDY DESIGN: MEDLINE, EMBASE, Web of Sciences, Scopus, ClinicalTrial.gov, OVID and Cochrane Library were searched for relevant articles from the inception to May 2018. All studies assessing PTEN expression as predictive marker in EH and EEC treated with progestin were included. Relative risk (RR) for therapy failure was calculated with 95% confidence interval (CI) and a significant p-value<0.05, with a subgroup analysis based on the histologic category (EEC or EH) and the administration route of progestin (oral or intrauterine). RESULTS: Seven cohort studies assessing 376 patients were included. PTEN loss was not significantly associated with the outcome of therapy in the overall analysis (RR = 1.24, 95% CI, 0.88-1.76, p = 0.21), in + the subgroups of EEC (RR = 0.89, 0.32-2.49, p = 0.83), EH (RR = 1.30, 0.90-1.87 p = 0.16), oral progestin (RR = 1.25 0.88-1.79, p = 0.22) and intrauterine device (RR = 1.02, 0.36-2.87, p = 0.97). CONCLUSION: PTEN seems not to be useful as predictive marker of response to the conservative treatment of EH and EC, regardless of the administration route (oral or intrauterine) of progestins. We advise future researcher not to further assess PTEN as a stand-alone predictive marker

Intrahepatic persistent fetal right umbilical vein: a retrospective study

Introduction: To appraise the incidence and value of intrahepatic persistent right umbilical vein (PRUV). Methods: This was a single-center study. Records of all women with a prenatal diagnosis of intrahepatic PRUV were reviewed. The inclusion criteria were women with gestational age greater than 13 weeks of gestation. Exclusion criteria were fetuses with situs abnormalities, due to the hepatic venous ambiguity, and extrahepatic PRUV. The primary outcome was the incidence of intrahepatic PRUV in our cohort. The secondary outcomes were associated malformations. Results: 219/57,079 cases (0.38%) of intrahepatic PRUV were recorded. The mean gestational age at diagnosis was 21.8 ± 2.9 weeks of gestations. PRUV was isolated in the 76.7%, while in 23.3% was associated with other major or minor abnormalities. The most common associated abnormalities were cardiovascular abnormalities (8.7%), followed by genitourinary abnormalities (6.4%), skeletal abnormalities (4.6%), and central nervous system abnormalities (4.1%). Within the cardiovascular abnormalities, the most common one was ventricular septal defect (six cases). Conclusion: In most cases PRUV is an isolated finding. Associated minor or major malformations are presented in the 23.3% of the cases, so this finding should prompt detailed prenatal assessment of the fetus, with particular regard to cardiovascular system

Cms gem detector material study for the hl-lhc

A study on the Gaseous Electron Multiplier (GEM) foil material is performed to determine the moisture diffusion rate, moisture saturation level and the effects on its mechanical properties. The study is focused on the foil contact with ambient air and moisture to determine the value of the diffusion coefficient of water in the foil material. The presence of water inside the detector foil can determine the changes in its mechanical and electrical properties. A simulated model is developed with COMSOL Multiphysics v. 4.3 [1] by taking into account the real GEM foil (hole dimensions, shapes and material), which describes the adsorption of water. This work describes the model, its experimental verification, the water diffusion within the entire sheet geometry of the GEM foil, thus gaining concentration profiles and the time required to saturate the system and the effects on the mechanical properties

Tuning the potential drop at graphene/protic ionic liquid interface by molecular structure engineering

Ionic liquids (ILs) have been extensively employed in many applications involving interfaces with carbon-based electrodes, such as energy storage devices (batteries or supercapacitors) or electrocatalytic devices, where the way each ion of the IL interacts with the electrode has a strong impact on the overall performance of the device. For instance, the amount of potential difference between the electrode and the bulk of the IL is highly sensitive to the IL composition and it is directly related to the device capacitance. The selection of the most suited pair of ions often proceeds by time-consuming and costly trial-and-error approaches. It is necessary to understand the atomistic features of the interface to determine the effect of each ion on the potential drop. By classical molecular dynamics simulations, we show that it is possible to quickly infer the interface potential arising at the carbon electrode by carefully inspecting the molecular structure of the IL. The ion orientation at the interface is, in fact, determined by the distribution of charges within the molecules. Depending on where charges are located, ions can either lie flat or perpendicular to the interface to minimize the surface energy. The interface potential is found to be mainly determined by ion-ion interactions dictating the interface energy minimization process, whereas ion-electrode interactions are found to enforce higher ordering and charge layers stacking but not to induce selective adsorption of an ion over the other

Prediction of the structural and electronic properties of MoxTi1−xS2 monolayers via first principle simulations

Two-dimensional transition metal dichalcogenides have gained great attention because of their peculiar physical properties that make them interesting for a wide range of applications. Lately, alloying between different transition metal dichalcogenides has been proposed as an approach to control two-dimensional phase stability and to obtain compounds with tailored characteristics. In this theoretical study, we predict the phase diagram and the electronic properties of MoxTi1−xS2 at varying stoichiometry and show how the material is metallic, when titanium is the predominant species, while it behaves as a p-doped semiconductor, when approaching pure MoS2 composition. Correspondingly, the thermodynamically most stable phase switches from the tetragonal to the hexagonal one. Further, we present an example which shows how the proposed alloys can be used to obtain new vertical two-dimensional heterostructures achieving effective electron/hole separation

Significant risk of occult cancer in complex non-atypical endometrial hyperplasia

BACKGROUND: In the 2014 WHO classification of endometrial hyperplasia (EH), complex EH is lumped together with simple EH in the benign category of non-atypical EH. OBJECTIVE: To assess the risk of coexistent cancer in complex EH and simple EH without atypia, through a systematic review and meta-analysis. METHODS: Electronic databases were searched from their inception to January 2019 for relevant articles. RESULTS: Twelve studies assessing a total of 804 non-atypical EH were included. The risk of coexistent cancer was significantly higher in complex EH (12.4%) than in simple EH (2%), with an OR of 6.03 (p = 0.0002). CONCLUSION: Even in the absence of cytologic atypia, complex EH is associated with a significant risk of coexistent cancer. Further studies are necessary to investigate the need for a revision in the WHO classification