Inferring Displacement Fields from Sparse Measurements Using the Statistical Finite Element Method

A well-established approach for inferring full displacement and stress fields from possibly sparse data is to calibrate the parameter of a given constitutive model using a Bayesian update. After calibration, a (stochastic) forward simulation is conducted with the identified model parameters to resolve physical fields in regions that were not accessible to the measurement device. A shortcoming of model calibration is that the model is deemed to best represent reality, which is only sometimes the case, especially in the context of the aging of structures and materials. While this issue is often addressed with repeated model calibration, a different approach is followed in the recently proposed statistical Finite Element Method (statFEM). Instead of using Bayes' theorem to update model parameters, the displacement is chosen as the stochastic prior and updated to fit the measurement data more closely. For this purpose, the statFEM framework introduces a so-called model-reality mismatch, parametrized by only three hyperparameters. This makes the inference of full-field data computationally efficient in an online stage: If the stochastic prior can be computed offline, solving the underlying partial differential equation (PDE) online is unnecessary. Compared to solving a PDE, identifying only three hyperparameters and conditioning the state on the sensor data requires much fewer computational resources. This paper presents two contributions to the existing statFEM approach: First, we use a non-intrusive polynomial chaos method to compute the prior, enabling the use of complex mechanical models in deterministic formulations. Second, we examine the influence of prior material models (linear elastic and St.Venant Kirchhoff material with uncertain Young's modulus) on the updated solution. We present statFEM results for 1D and 2D examples, while an extension to 3D is straightforward.Comment: 29 pages, 15 figures, Preprint submitted to Elsevie

Mini Sling (Ophira) versus Pubovaginal Sling for Treatment of Stress Urinary Incontinence: A Medium-term Follow-up

To compare two different procedures, mid-urethral mini sling (Ophira) and autologous rectus fascia sling, according to their medium-term subjective and objective outcome and satisfaction rates in the treatment of stress urinary incontinence in women. One hundred women with the main complaint of stress urinary incontinence were randomized to be treated with either mini sling (Ophira) or autologous rectus facia pubovaginal sling. Preoperative evaluation consisted of: physical examination, blood biochemistry urine analysis and culture, urinary tract ultrasound scan, conventional multi-channel urodynamic study, cystourethroscopy, cough induced stress test and Incontinence Impact Questionnaire (IIQ). The patients were objectively and subjectively re-evaluated at 1, 3, 6 and 12 postoperative months and the last visit and the collected data of more than one year follow-up were compared with preoperative assessments. Seventy two out of one hundred patients were followed for a mean time of 13.8±4.4 months (12-20 months range). Objective cure rate, according to cough-induced stress test was recorded in 88.6% and 89.2% of the mini sling (Ophira) and the rectus facia sling group respectively (P=1.0). Postoperative mean IIQ score decreased to 42.7±11.4 and 50.2±11.1 in the mini sling (Ophira) group versus rectus facia pubovaginal sling (P=0.007). Twenty eight (80%) and 23 (67%) patients in the mini sling (Ophira) and rectus facia pubovaginal sling were satisfied with the operation (P=0.23). There is no significant difference between the mini sling (Ophira) and autologous rectus fascia sling procedure in the treatment of stress urinary incontinence at medium-term follow-up

The frequency of AgNOR (Argyrophilic Nucleoli Organizer Region) points in differentiation between the benign prostatic hyperplasia and prostatic adenocarcinoma

Background: While the differentiation of prostatic adenocarcinoma and benign prostatic hyperplasia (BPH) is not often a difficult task, sometimes it is not the case even for the experienced pathologists. In this study the efficacy of AgNOR staining technique for differentiating between the prostatic adenocarcinoma and BPH were evaluated. Materials & Methods: Using a descriptive study 15 prostatic adenocarcinoma samples (without spot to histologic grade) and 15 BPH samples were selected and stained with AgNOR method. Specimens were taken from paraffin block in Pathology laboratory archive. Results: The average AgNOR points in BPH and prostatic adenocarcinoma were1.39 and 2.48 per cell, respectively. In BPH there was one or two points of AgNOR with specific margin but in prostatic adenocarcinoma numerous arranged AgNOR points were seen. While the number of cells in BPH with three or more AgNOR points were 4.7, in prostatic adenocarcinoma it was 41.47. Conclusion: AgNOR is a useful method to differentiate between benign prostatic hyperplasia and prostatic adenocarcinoma

Role of the gonadal vessels on the stone lodgment in the proximal ureter: Direct observation during laparoscopic ureterolithotomy

Introduction: Previous radiological studies revealed that stones lodge more frequently in the ureterovesical junction (UVJ) as well as the proximal ureter. Factors that prevent stone passage from the proximal ureter are not well studied. Aim: To explore the site of the lodged stones in the proximal ureter with direct observation during laparoscopic ureterolithotomy. Materials and methods: Between November 2014 and February 2015, we included 26 patients including 18 men and 8 women with stones larger than 10 millimeters in the proximal ureter who were candidate for laparoscopic ureterolithotomy. We prospectively recorded the site of the lodged stones in the ureter during laparoscopic ureterolithotomy in relation with the sites of ureteral stenosis as well as the gonadal vessels. Results: Among 26 patients with ureteral stone, in 19 cases stone was found close to the gonadal vein compared with seven cases that stone was in other locations of the ureter (p = 0.02). The characteristics of patients and stones were not different in cases that the stone was close to gonadal vessels compared with other locations. Conclusions: This study showed that most of the stones lodged in the proximal ureter were in close proximity with gonadal vessels. Gonadal vessels may be an extrinsic cause of ureteral narrowing

Serum and 24-hour urinary tests cost-effectiveness in stone formers

Objective To assess the routine serum and 24-hour urine tests proficiency in diagnosing the baseline metabolic abnormality of kidney stone formers. Methods This study analyzes the routine serum and 24-hour urine tests proficiency in diagnosing the baseline metabolic abnormality of kidney stone formers. The sensitivity and specificity, false positive, and negative results of the tests are extracted from diagnostic kits used in the laboratories of the target community. To accurately infer the results, a simulation based on 1000 people was used through 22 standard laboratory tests (Additional File 2), including calcium, oxalate, phosphate, uric acid, sulfate, potassium, sodium, citrate, and magnesium in 24-hour urine; and calcium, creatinine, Vit D, uric acid, and intact parathyroid hormone (PTH) in serum. The incremental cost-effectiveness ratio (ICER) was calculated and compared for each diagnostic test versus other diagnostic tests according to the incremental cost required for correct diagnoses of stone causes. Results Urinary uric acid, citrate, and serum potassium constitute the cost-effectiveness boundary curve in this study. This means that other diagnostic tests are not cost-effective compared to these three tests in terms of indexing at least one item of cost and effectiveness. The ICER index for each correct diagnosis with the urinary uric acid test was $ 1.25 per diagnosis, the most cost-effective test compared to serum potassium and urinary citrate. Conclusion The simplified blood and 24-hour urine metabolic evaluation, including urinary uric acid, citrate, and serum potassium, constitute the cost-effectiveness boundary curve. The most cost-effective test was urinary uric acid measurement

Propranolol decreases the post-operative pain and analgesic administration following abdominal hysterectomy

Post-operative pain results in many complications. Studies suggest beta blockers to be effective in decreasing postoperative pain and analgesic requirements. This study evaluated the influence of perioperative administration of 40mg orally propranolol on patients' post-operative pain score and analgesic consumption following abdominal hysterectomy. In this double-blind randomized clinical trial, 73 women who had referred for elective abdominal hysterectomy surgery during years 2010-2011 were reviewed. Patients were randomly divided into case (receiving 40 mg orally propranolol tablet 30 min before surgery) and control (receiving orally placebo 30 min before surgery). General anesthesia was done the same for both groups. Postoperative time of first need to morphine, total morphine consumption dose and pain severity during the first 24 hours after surgery was measured among both groups. age and hysterectomy indication was not statistically different between two groups (p>0.05). Total morphine consumption in the propranolol group (2.85±2.5 mg) was lower than control group (10.35±2.2 mg) (p<0.001). The Initial morphine administration time (min) in the propranolol group was significantly longer than the control group (998.7 ± 49 vs. 261.7 ± 139.1) (p<0.001). The Pain Score (VAS scoring) (Mean±SD) in propranolol group was lower than the control group (1.03±0.58 vs. 2.76 ±0.8) (p< 0.001). administration of 40mg orally propranolol 30 minutes before abdominal hysterectomy is effective in decreasing patients' post-operative pain and morphine administration dosage. It also elongates the Initial morphine administration time in the first 24 hours following abdominal hysterectomy

Supplementary Material for: Bladder Paraganglioma Presenting as post-Micturition Palpitations: A case report

Introduction: paraganglioma of the urinary bladder (PUB) is an extremely rare extra-adrenal catecholamine-secreting neuroendocrine tumor, accounting for only 0.05% of all bladder tumors and 1% of all pheochromocytomas. The clinical presentation of PUB can be diverse and challenging to diagnose. Case Presentation: This case report presents a 37-year-old man with post-micturition palpitation, headache, and sweating, with no history of hematuria or other irritative urinary symptoms. Ultrasound and contrast-enhanced computed tomography (CECT) revealed a suspicious mass in the right posterolateral wall of the urinary bladder. Despite normal functional hormonal tests, the diagnosis of PUB was confirmed after surgical enucleation and histopathological examination. Conclusion: This report emphasizes the importance of considering PUB as a differential diagnosis in patients with post-micturition symptoms and paroxysmal hypertension, as well as the need for a multidisciplinary approach in the evaluation and management of such rare and complex cases. Early recognition and surgical intervention are crucial for optimal management and favorable clinical outcomes

Fluoroscopy-free ultrasonography-guided percutaneous nephrolithotomy in pediatric patients: a single-center experience

Objectives: To present the safety and efficacy of fluoroscopy-free ultrasound-guided PCNL for the treatment of renal calculi in pediatric patients of all ages. Methods: 30 children with mean age of 5 years (6 months–12 years) underwent totally ultrasound-guided PCNL from March 2013 to August 2016. The pyelocalyceal system was punctured in prone position using only ultrasonography guidance, and the tract was dilated using a single shot dilation technique. No fluoroscopy was used during any of the stages of renal access. The procedure was performed using adult-sized instruments. Results: The mean stone size was 27.1 ± 8.7 mm. Mean access time was 4.3 ± 2 min. Mean nephroscopic time was 34.6 ± 15.2 min. Mean hospital stay of patients was 3 days (range 2–5). 21 patients were stone-free after the procedure (70 success rate). Only four patients out of 30 experienced postoperative complications. Conclusions: The results of this study showed that fluoroscopic-free ultrasound-guided PCNL in pediatric patients of all ages is safe, highly efficient, and minimizes potential radiation exposure risks associated with the procedure. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature