Finite element simulation of the complete sheet metal blanking cycle: Effect of blanking clearance on force curve and cut edge quality.

Sheet metal blanking process is a manufacturing process that is widely used in sheet metal forming and particularly in the electronics and automotive industries. The outcome and quality of the blanked parts are affected by various parameters such as the blanking clearance, the sheet metal mechanical properties and the wear of tools. However, experimental campaigns to assess the effects of these parameters on the process outcome can be prohibitively expensive for the industry. As a result, numerical simulation of the blanking process is becoming increasingly important to gain insight into the process and study these effects. The present paper provides a novel finite element (FE) simulation procedure to predict the complete blanking cycle including sheet metal cutting, sheet metal springback, punch penetration in die, and stripping phases. A blanking force curve showing the punch force at all phases can thus be obtained. The commercial finite element code ABAQUS® has been chosen to develop this procedure using ABAQUS/Explicit® code for the cutting phase and ABAQUS/Standard® code for the remaining phases. Based on this procedure, the influence of the blanking clearance on the punch force-displacement curve and on the cut edge quality has been studied. The obtained results have been compared to previous literature results and experimental findings.

Surgical management of biconcave glenoids: a scoping review.

Biconcave (B2) glenoids, characterized by significant posterior glenoid bone loss and a biconcave wear pattern, are a challenging pathology in shoulder surgery. Significant bone defects present in B2 glenoids increases the risk of complications and rates of failure for operative patients with glenohumeral osteoarthritis. Diagnosing this entity is of pivotal importance, and can be accomplished with imaging and a comprehensive clinical investigation. There are no clear-cut guidelines for management, but options include hemiarthroplasty, anatomic total shoulder arthroplasty, and reverse shoulder arthroplasty. In recent years, modern techniques such as corrective reaming, bone grafts, and the use of augmented components have improved patient outcomes. Educating prospective patients is essential for reaching a shared management decision, setting appropriate expectations, and optimizing prognostic outcomes.

An alternative formulation of Coxian phase-type distributions with covariates: Application to emergency department length of stay.

In this article, we present a new methodology to model patient transitions and length of stay in the emergency department using a series of conditional Coxian phase-type distributions, with covariates. We reformulate the Coxian models (standard Coxian, Coxian with multiple absorbing states, joint Coxian, and conditional Coxian) to take into account heterogeneity in patient characteristics such as arrival mode, time of admission, and age. The approach differs from previous research in that it reduces the computational time, and it allows the inclusion of patient covariate information directly into the model. The model is applied to emergency department data from University Hospital Limerick in Ireland, where we find broad agreement with a number of commonly used survival models (parametric Weibull and log-normal regression models and the semiparametric Cox proportional hazards model).

Which Surgical Operations Should be Performed in District Hospitals in East, Central and Southern Africa? Results of a Survey of Regional Clinicians.

BACKGROUND: In East, Central and Southern Africa (ECSA), district hospitals (DH) are the main source of surgical care for 80% of the population. DHs in Africa must provide basic life-saving procedures, but the extent to which they can offer other general and emergency surgery is debated. Our paper contributes to this debate through analysis and discussion of regional surgical care providers' perspectives. METHODS: We conducted a survey at the College of Surgeons of East, Central and Southern Africa Conference in Kigali in December 2018. The survey presented the participants with 59 surgical and anaesthesia procedures and asked them if they thought the procedure should be done in a district level hospital in their region. We then measured the level of positive agreement (LPA) for each procedure and conducted sub-analysis by cadre and level of experience. RESULTS: We had 100 respondents of which 94 were from ECSA. Eighteen procedures had an LPA of 80% or above, among which appendicectomy (98%), caesarean section (97%) and spinal anaesthesia (97%). Twenty-one procedures had an LPA between 31 and 79%. The surgical procedures that fell in this category were a mix of obstetrics, general surgery and orthopaedics. Twenty procedures had an LPA below 30% among which paediatric anaesthesia and surgery. CONCLUSION: Our study offers the perspectives of almost 100 surgical care providers from ECSA on which surgical and anaesthesia procedures should be provided in district hospitals. This might help in planning surgical care training and delivery in these hospitals.

Immunohistochemical evidence of dysregulation of the mammalian target of rapamycin pathway in primary and metastatic pheochromocytomas.

OBJECTIVE: To characterize the status of the mammalian target of rapamycin pathway using formalin-fixed, paraffin-embedded specimens from patients with primary and metastatic pheochromocytoma. METHODS: Tissue microarrays were built from 19 normal adrenal medullas, 39 primary pheochromocytomas, and 8 unrelated metastatic pheochromocytomas. In 2 of the 8 cases of metastatic pheochromocytoma tissues, samples from the primary tumor were available. The expression levels of phosphatase and tensin homolog, phosphorylated Akt, phosphorylated S6, p27, and c-myc were evaluated by immunohistochemistry. RESULTS: The levels of phosphatase and tensin homolog and p27 were greater in the nontumor tissue than in the primary and metastatic pheochromocytomas. Increasing levels of phosphorylated Akt were noted in the nontumor adrenal medulla, primary pheochromocytomas, and metastatic pheochromocytomas. Finally, the levels of phosphorylated S6 were greater in the metastatic pheochromocytomas than in the nontumor adrenal medulla and primary pheochromocytomas. CONCLUSION: We found evidence of dysregulation of the mammalian target of rapamycin pathway in primary and metastatic pheochromocytomas, with increased phosphorylated S6 and phosphorylated Akt, and decreased phosphatase and tensin homolog and p27 expression levels. Because the currently available treatment modalities are less than optimal, our findings lend additional support to continuing to explore the utility of mammalian target of rapamycin pathway-targeted therapy for pheochromocytomas.