Wake control of a 3D bluff body

Bluff bodies are characterized by massive flow separation responsible of most of the pressure drag. Three main contributions roughly determine the total amount of the body drag : 30% is due to the rolling tire, 45% derive from the rear base and 25% comes from the underbody flow and interferences. In the case of large and medium size trucks employed for short and long distance of transportations the fuel consumption can be considerable reduced through the control of the flow separation from the base. The afterbody geometry plays a key role for the drag contributions as showed by Ahmed [1]. Aider et al. [2] used passive vortex generators while piezoelectric vortex generators were investigated by Orazi et al. [3]. Continuous blowing slots as done by Rouméas et al. [4] have been also used on a semi-infinite body. The present investigation considers a simplified 3D car with square-back rear shape. The wake control consist in the injection of continuous jets through four rectangular slots mounted around the perimeter of the rear part. Furthermore, four curved slots are disposed near the wheel to control the flow separation in this region. The flow analysis is performed by means of CFD commercial code (STAR CCM+® by Cd-Adapco). Results of this preliminary investigation will be presented. The effects of the independent rear slots orientation (i) and of the jet velocity (Vi) are analyzed as well as the effects of the jets around the wheels. The study will be also carry out on a physical model that will be tested in a wind tunnel. In figure 1 the expanded model and a portion of the longitudinal section of the rear part of the body are shown

Wind tunnel investigation on a squared–back commercial vehicle

The assessment of an appropriate methodology for a wind tunnel investigation on a square back vehicle model is presented and discussed. The CD−Re curve is evaluated in order to identify the adequate range of Reynolds number for the tests. The drag coefficient value is attested at CD = 0.465 which is in accordance with the literature results for the same category of vehicles considered. The repeatability and the accuracy of the CD have been analyzed through a campaign of measurements and an error propagation analysis is dedicated to associate the correct uncertainty to the drag coefficient values. The analysis of statistical convergence of the measured quantities is also carried out in order to fix the adequate acquisition time. The results of the experimental investigation regarding the measurement methodology, drag coefficient, base pressure distribution, position of the center of pressure, and wake measurements are presented highlighting the main natural flow features. Moreover, the pressure fluctuations measured by microphone sensors allowed to evidence the unsteadiness and possible flow configurations involving the entire rear part

Functional Role of miR-155 in the Pathogenesis of Diabetes Mellitus and Its Complications

Substantial evidence indicates that microRNA-155 (miR-155) plays a crucial role in the pathogenesis of diabetes mellitus (DM) and its complications. A number of clinical studies reported low serum levels of miR-155 in patients with type 2 diabetes (T2D). Preclinical studies revealed that miR-155 partakes in the phenotypic switch of cells within the islets of Langerhans under metabolic stress. Moreover, miR-155 was shown to regulate insulin sensitivity in liver, adipose tissue, and skeletal muscle. Dysregulation of miR-155 expression was also shown to predict the development of nephropathy, neuropathy, and retinopathy in DM. Here, we systematically describe the reports investigating the role of miR-155 in DM and its complications. We also discuss the recent results from in vivo and in vitro models of type 1 diabetes (T1D) and T2D, discussing the differences between clinical and preclinical studies and shedding light on the molecular pathways mediated by miR-155 in different tissues affected by DM

Psychosocial predictors of upper extremity transplantation outcomes: A review of the international registry 1998–2016

Background: Upper extremity transplantation (UET) is becoming increasingly common. This article attempts to collate data from cases contributing to the International Registry on Hand and Composite Tissue Transplantation (IRHCTT), define psychosocial themes perceived as predictors of success using statistical methods, and provide an objective measure for optimization and selection of candidates. Methods: The IRHCTT provided anonymous data on UET recipients. A supple- mentary psychosocial survey was developed focusing on themes of depression, posttraumatic stress disorder (PTSD), anxiety, interpersonal functioning and dependence, compliance, chronic pain, social support, quality of life, and patient expectations. We determined the risk of transplant loss and psychological factors associated with higher risk of transplant loss. Results: Sixty-two UET recipients reported to the IRHCTT. Forty-three psychoso- cial surveys (68%) were received, with 38 (88%) having intact transplants and 5 (12%) being amputated. Among recipients with a diagnosis of anxiety (N = 29, 67%), 5 (17%) reported transplant loss (P = 0.03). Among those with depression (N = 14, 33%), 2 recipients (14%) has transplant loss (P = 0.17); while 4 recipients (22%) with PTSD (N = 18, 42%) had transplant loss (P = 0.01). Of participants active in occupational therapy (N = 28, 65%), 2 (7%) reported transplant loss (P = 0.09). Of recipients with realistic functional expectations (N = 34, 79%), 2 (6%) had transplant loss versus 3 (34%) who were felt to not have realistic expec- tations (N = 9, 21%, P = 0.05). Recipients with strong family support (N = 33, 77%) had a lower risk of transplant loss compared with poor or fair family support (N = 10, 23%), but did not reach statistical significance (6% versus 30%, P = 0.14). Conclusion: Anxiety, depression, PTSD, participation in occupational therapy, expectations for posttransplant function, and family support are associated with postsurgical transplant status

Trapped vortex cell for aeronautical applications: flow analysis through PIV and Wavelet transform tools.

Abstract Results of the application of a trapped vortex cell to an airfoil with the aim of improving the aerodynamic performances are presented for two complementary experiments arranged at CIRA and at Politecnico di Torino. In the CIRA experiments, PIV measurements on a simplified configuration were carried out to characterize the trapped vortical structure and its effect on the separating flow downstream of the cell. In the experimental investigation at Politecnico di Torino, static pressure distributions were measured around a complete airfoil model, to yield lift and pitching moment coefficients. Wake surveys were also carried out to measure the drag. To study the unsteady phenomena inside the cavity pressure fluctuations signals were also investigated using Kulite sensors. In both experiments, the angle of attack of the airfoil and the Reynolds number were varied. It is shown that the flow inside the cell is highly unsteady with significant shedding of flow structures downstream. This phenomenon results in a large region of separated flow, in higher drag and lower lift. By contrast, the cell flow is considerably stabilized and regularized by applying distributed suction over the cell wall. As a result, the flow downstream of the cell reattaches and lower drag and larger lift are observed

Telemonitoring in heart failure patients treated by cardiac resynchronisation therapy with defibrillator (CRT-D): the TELECART Study

Aim: Telemonitoring (TM) is a safe and efficient monitoring system for internal cardioverter defibrillator device (ICD) recipients. TM has been used to track info on the clinical status of heart failure patients treated by ICD and/or cardiac resynchronisation therapy defibrillator (CRT-D). The aim of this study was to investigate the impact of TM on clinical outcomes in a population of CRT-D patients with heart failure. Methods: In a multicentre, randomised study, patients with chronic heart failure, New York Heart Association (NYHA) functional class II or III, left bundle branch block, severe left ventricle ejection fraction reduction (LVEF < 35%) have been identified and screened. Results: One hundred and ninety-one patients have been randomised to receive either a CRT-D with TM or a CRT-D with traditional ambulatory monitoring (control group) and completed the 12-month study follow-up. Primary endpoints were all cause death, cardiac death and hospital admission for heart failure. Secondary endpoints were atrial fibrillation, sustained episodes, non-sustained and self terminated ventricular tachyarrhythmia, sustained ventricular tachycardia, and ventricular fibrillation, ICD shocks and percentage of CRT-D responder patients. Univariate analysis identified the following factors predicting hospitalisation: TM, age, chronic kidney disease, hypercholesterolaemia, LVEF and NYHA class. At multivariate analysis, TM was the only factor predicting heart failure hospitalisation (hazard ratio 0.6, 0.42–0.79, 95% CI, p = 0.002), without affecting overall mortality and cardiac deaths events. Conclusions: Taken together, our data indicate the importance of TM in predicting heart failure hospitalisation in patients treated with CRT-D

Preoperative assessment of cardiovascular risk in patients undergoing noncardiac surgery: The Orion study

In patients undergoing noncardiac surgery risk indices can estimate patients' perioperative risk of major cardiovascular complications. The indexes currently in use were derived from observational studies that are now outdated with respect to the current clinical context. We undertook a prospective, observational, cohort study to derive, validate, and compare a new risk index with established risk indices. We evaluated 7335 patients (mean age 63±13 years) who underwent noncardiac surgery. Based on prospective data analysis of 4600 patients (derivation cohort) we developed an Updated Cardiac Risk Score (UCRS), and validated the risk score on 2735 patients (validation cohort). Four variables (i.e. the UCRS) were significantly associated with the risk of a major perioperative cardiovascular events: high-risk surgery, preoperative estimate glomerular filtration rate &lt;30 ml/min/1.73 m2, age ≥75 years, and history of heart failure. Based on the UCRS we created risk classes 1,2,3 and 4 and their corresponding 30-day risk of a major cardiovascular complication was 0.8% (95% confidence interval [CI] 0.5-1.7), 2.5 (95% CI 1.6-5.6), 8.7 (95% CI 5.2-18.9) and 27.2 (95% CI 11.8-50.3), respectively. No significant differences were found between the derivation and validation cohorts. Receiver operating characteristic (ROC) curves demonstrate a high predictive performance of the new index, with greater power to discriminate between the various classes of risk than the indexes currently used. The high predictive performance and simplicity of the UCRS make it suitable for wide-scale use in preoperative cardiac risk assessment of patients undergoing noncardiac surgery