Prediction of dynamic strains on a monopile offshore wind turbine using virtual sensors

The monitoring of the condition of the offshore wind turbine during its operational states offers the possibility of performing accurate assessments of the remaining life-time as well as supporting maintenance decisions during its entire life. The efficacy of structural monitoring in the case of the offshore wind turbine, though, is undermined by the practical limitations connected to the measurement system in terms of cost, weight and feasibility of sensor mounting (e.g. at muddline level 30m below the water level). This limitation is overcome by reconstructing the full-field response of the structure based on the limited number of measured accelerations and a calibrated Finite Element Model of the system. A modal decomposition and expansion approach is used for reconstructing the responses at all degrees of freedom of the finite element model. The paper will demonstrate the possibility to predict dynamic strains from acceleration measurements based on the aforementioned methodology. These virtual dynamic strains will then be evaluated and validated based on actual strain measurements obtained from a monitoring campaign on an offshore Vestas V90 3 MW wind turbine on a monopile foundation

An investigation of the mechanica behaviour of carbon epoxy cross ply cruciform specimens under biaxial loading

Abstract: In the present study carbon epoxy cruciform type specimens with a cross ply lay up, were biaxially and uniaxially loaded in their plane using four independent servo-hydraulic actuators. Four different biaxial loading ratios were investigated while the applied load was quasistatic. A comparison between experimental observations for the strain evolution of the biaxially loaded central section of the specimen coming from digital image correlation measurements (DIC) and a three dimensional finite element damage model (FEDM) will be shown. Furthermore the failure loads coming from the load shells of the machine were straightforward compared with the output of the FEDM

Aprotinin reduces cardiac troponin I release and inhibits apoptosis of polymorphonuclear cells during off-pump coronary artery bypass surgery

Objectives: In addition to blood-sparing effects, aprotinin may have cardioprotective and anti-inflammatory effects during cardiopulmonary bypass-assisted cardiac surgery. In this study, the authors examined whether aprotinin had cardioprotective and/or anti-inflammatory effects in patients undergoing off-pump coronary artery bypass grafting. Design: A prospective randomized clinical trial. Setting: University hospital. Participants: Fifty patients were randomized to control (n = 25) or aprotinin treatment (n = 25) groups. Interventions: Aprotinin was given as a loading dose (2 x 10(6) KIU) followed by a continuous infusion at 5 x 10(5) KIU/h until skin closure. Measurements and Main Results: Blood samples for cardiac troponin I; interleukin-6, interleukin-8, and interleukin-10; tumor necrosis factor a; and elastase were taken after anesthesia induction, completion of revascularization, and 6 hours, 12 hours, and 24 hours after revascularization. Blood samples were taken to assess for apoptosis in polymorphonuclear cells. Baseline plasma levels for cardiac troponin I did not differ between groups but were significantly lower in aprotinin-treated patients at the time of revascularization (P = 0.03) and 6 hours (p = 0.004) and 24 hours (p = 0.03) later. Aprotinin significantly reduced apoptosis in polymorphonuclear cells compared with control-treated patients (p = 0.04). There were no differences in plasma cytokine or elastase levels between groups. Conclusions: The authors conclude that aprotinin reduces perioperative cardiac troponin I release and attenuates apoptosis in polymorphonuclear cells but has no significant effects on plasma cytokine levels in patients undergoing off-pump coronary artery bypass graft surgery

Systematic review of high-intensity focused ultrasound ablation in the treatment of breast cancer

Background A systematic review was undertaken to assess the clinical efficacy of non-invasive high-intensity focused ultrasound (HIFU) ablation in the treatment of breast cancer. Methods MEDLINE/PubMed library databases were used to identify all studies published up to December 2013 that evaluated the role of HIFU ablation in the treatment of breast cancer. Studies were eligible if they were performed on patients with breast cancer and objectively recorded at least one clinical outcome measure of response (imaging, histopathological or cosmetic) to HIFU treatment. Results Nine studies fulfilled the inclusion criteria. The absence of tumour or residual tumour after treatment was reported for 95·8 per cent of patients (160 of 167). No residual tumour was found in 46·2 per cent (55 of 119; range 17-100 per cent), less than 10 per cent residual tumour in 29·4 per cent (35 of 119; range 0-53 per cent), and between 10 and 90 per cent residual tumour in 22·7 per cent (27 of 119; range 0-60 per cent). The most common complication associated with HIFU ablation was pain (40·1 per cent) and less frequently oedema (16·8 per cent), skin burn (4·2 per cent) and pectoralis major injury (3·6 per cent). MRI showed an absence of contrast enhancement after treatment in 82 per cent of patients (31 of 38; range 50-100 per cent), indicative of coagulative necrosis. Correlation of contrast enhancement on pretreatment and post-treatment MRI successfully predicted the presence of residual disease. Conclusion HIFU treatment can induce coagulative necrosis in breast cancers. Complete ablation has not been reported consistently on histopathology and no imaging modality has been able confidently to predict the percentage of complete ablation. Consistent tumour and margin necrosis with reliable follow-up imaging are required before HIFU ablation can be evaluated within large, prospective clinical trials. Many questions remai

Examination of potential novel biochemical factors in relation to prostate cancer incidence and mortality in UK Biobank

Background: Although prostate cancer is a leading cause of cancer death, its aetiology is not well understood. We aimed to identify novel biochemical factors for prostate cancer incidence and mortality in UK Biobank. Methods: A range of cardiovascular, bone, joint, diabetes, renal and liver-related biomarkers were measured in baseline blood samples collected from up to 211,754 men at recruitment and in a subsample 5 years later. Participants were followed-up via linkage to health administrative datasets to identify prostate cancer cases. Hazard ratios (HRs) and 95% confidence intervals were calculated using multivariable-adjusted Cox regression corrected for regression dilution bias. Multiple testing was accounted for by using a false discovery rate controlling procedure. Results: After an average follow-up of 6.9 years, 5763 prostate cancer cases and 331 prostate cancer deaths were ascertained. Prostate cancer incidence was positively associated with circulating vitamin D, urea and phosphate concentrations and inversely associated with glucose, total protein and aspartate aminotransferase. Phosphate and cystatin-C were the only biomarkers positively and inversely, respectively, associated with risk in analyses excluding the first 4 years of follow-up. There was little evidence of associations with prostate cancer death. Conclusion: We found novel associations of several biomarkers with prostate cancer incidence. Future research will examine associations by tumour characteristics.</p

Overall survival, disease-specific survival and local recurrence outcomes in patients with muscle-invasive bladder cancer treated with external beam radiotherapy and brachytherapy: a systematic review

Introduction: Neoadjuvant chemotherapy followed by radical cystectomy (RC) and pelvic lymph node dissection is the standard radical management for muscle‐invasive bladder cancer (MIBC). However, major pelvic surgery is not suitable for all patients and combined modality therapy (CMT) offers an alternative for patients who want to retain their bladder. Brachytherapy (BT), as part of CMT, has been offered in selective cases of bladder cancer. Objectives: To evaluate the clinical effectiveness of BT for solitary urinary bladder tumours in terms of survival, local recurrence (LR) rates, and adverse events. Methods: A systematic review was conducted using defined search terms using online databases. Articles that discussed the use of BT as part of multi‐modality treatments for MIBC were included. Results: Searches returned 112 articles of which 20 were deemed suitable for analysis. In all, 15 of the 20 articles reported overall survival (OS) at 5 years, 2747 patients were at risk and 1670 were alive after 5 years (60%): seven studies reported OS at 10 years, with 817 patients at risk and 350 alive at 10 years (42%). Disease‐specific survival at 5 years was reported in four studies, with 371 patients at risk and 279 alive (75%) at 5 years. LR rates were reported across all 20 studies and ranged from 0% to 32%. Conclusion: Brachytherapy as part of CMT for MIBC is not a standard technique. It is an effective treatment in experienced centres for a selected patient population who wish to preserve their bladder. In such patients, CMT‐BT is well tolerated with an acceptable safety profile

Toward an MRI-based nomogram for the prediction of transperineal prostate biopsy outcome: A physician and patient decision tool

PURPOSE: To develop and internally validate a nomogram using biparametric magnetic resonance imaging (B-MRI)-derived variables for the prediction of prostate cancer at transperineal sector-guided prostate biopsy (TPSB). SUBJECTS/PATIENTS AND METHODS: Consecutive patients referred to our institution with raised prostate-specific antigen (PSA), abnormal prostate examination, or persistent suspicion of prostate cancer after previous transrectal biopsy between July 2012 and November 2015 were reviewed from a prospective database. All patients underwent prebiopsy B-MRI with T2-weighted and diffusion-weighted imaging sequences, followed by 24 to 40 core TPSB with additional targeted cores using cognitive registration. Univariable and multivariable logistic regression analysis was used to determine predictors of prostate cancer outcomes. Multivariable coefficients were used to construct 2 MRI-based nomograms to predict any and significant (Gleason 4 or maximum cancer core length ≥6mm) prostate cancer at TPSB. Bootstrap resamples were used for internal validation. Accuracy was assessed by calculating the concordance index. RESULTS: In total, 615 men were included in the study. Prostate cancer was diagnosed in 317 (51.5%) men with significant cancer diagnosed in 237 (38.5%) men. Age, Prostate Imaging Reporting and Data System (PI-RADS) score, PSA, PSA density, and primary biopsy were predictors of prostate cancer at TPSB on univariable analysis (P<0.0001). PSA showed strong correlation with PSA density and was excluded. The remaining variables were all independent predictors of prostate cancer on multivariable analysis (P<0.0001) and used to generate the nomograms. Both nomograms showed good discrimination for prostate cancer, with a concordance index of 87% for any cancer and 92% for significant disease. Using a nomogram-derived probability threshold of<15%, 111 (18.0%) biopsies can be saved, at the expense of 3 missed significant prostate cancers. CONCLUSIONS: These internally validated MR-based nomograms were able to accurately predict TPSB outcomes for prostate cancer, especially significant disease. Our findings support the combination of prebiopsy MRI results and clinical factors as part of the biopsy decision-making process