Design of a kite controller for airborne wind energy

Airborne wind energy is a field of technology being developed to make use of the vast, renewable wind power resource which is above the reach of traditional wind turbines, without the need for a large tower. Much analytical research has been undertaken in recent years to better understand the problem space. However, there are relatively few working systems that demonstrate their functioning and can be compared with simulations and theory. Off-grid power systems still rely heavily on diesel generators, so devices that tap renewable energy sources with similar ease of deployment and lower cost of energy would help this sector to reduce its reliance on expensive, polluting, fossil fuels. The development of these systems is often performed by teams with business interests leaving little open access content available regarding the design process of such devices or the data that they provide. A kite control pod has been designed for the remote control of a standard kitesurfing kite and a prototype has been demonstrated stably flying such a kite on a fixed length tether. This pod and kite would be tethered to a winch and as the kite flies across the wind, the lift force generated is applied to the winch which is reeled out and electrical power generated. Once fully extended, the tether would be reeled in with the kite de-powered, using some of the generated energy, stored in a battery. This system can then be used as a test bed for the further development of a compact, autonomous, airborne wind energy system for off-grid applications

Effectiveness of D-mannose, Hibiscus sabdariffa and Lactobacillus plantarum therapy in prevention of infectious events following urodynamic study

The urodynamic study is an invasive examination that allows a thorough evaluation of the functional activity of the lower urinary tract (bladder, urethra). The execution of urodynamic study exposes the patient to the risk of contracting infections of the lower urinary tract. Prevention of urinary tract infections consists in the avoidance of risk factors and prophylaxis with antimicrobial and non-antimicrobial measures. In this article, we aimed to evaluate the effectiveness of a phytotherapeutic product composed of D-mannose, Hibiscus sabdariffa, and Lactobacillus plantarum in the prevention of infectious events following invasive urodynamic examination.Introduction and aim: The urodynamic study is an invasive examination that allows a thorough evaluation of the functional activity of the lower urinary tract (bladder, urethra). The execution of urodynamic study exposes the patient to the risk of contracting infections of the lower urinary tract. Prevention of urinary tract infections consists in the avoidance of risk factors and prophylaxis with antimicrobial and non-antimicrobial measures. In this article, we aimed to evaluate the effectiveness of a phytotherapeutic product composed of D-mannose, Hibiscus sabdariffa, and Lactobacillus plantarum in the prevention of infectious events following invasive urodynamic examination. Materials and methods: We selected 100 female consecutive patients (age 19-87 years) that underwent urodynamic invasive procedure. We prescribed 14-day therapy with D-mannose, H. sabdariffa, and L. plantarum to these 100 patients after urodynamic invasive test. After that, we have examined urine cultures and urinary symptoms through telephone interviews and hospital outpatient visits to evaluate the possible presence of urinary tract infections. Results: Urinary tract infections were observed through urine culture in 13% of the selected patients; of the 13 urinary tract infections, 9 were observed in patients with urinary tract recurrent infections in the last year and the other 4 cases were associated with patients with no urinary infection in the last year. Three women reported some urinary symptoms and underwent antibiotic therapy. The other 10 cases were classified as asymptomatic bacteriuria. Three cases were related to patients presenting with pelvic organ prolapse. Eight cases were instead related to significant post-voiding residue (>100). Six patients with urinary tract infection reported constipation in the last year. All patients completed the prescribed therapy due to the affordable price of the product and no side effects have been reported. Conclusion: Our study about the administration of D-mannose, H. sabdariffa, and L. plantarum after invasive urodynamic examination underlined how this phytotherapeutic product can reduce the risk of bacteriuria and urinary tract infection in women

Survey of transfemoral amputee experience and priorities for the user-centered design of powered robotic transfemoral prostheses

BACKGROUND: Transfemoral amputees experience a complex host of physical, psychological, and social challenges, compounded by the functional limitations of current transfemoral prostheses. However, the specific relationships between human factors and prosthesis design and performance characteristics have not yet been adequately investigated. The present study aims to address this knowledge gap. METHODS: A comprehensive single-cohort survey of 114 unilateral transfemoral amputees addressed a broad range of demographic and clinical characteristics, functional autonomy, satisfaction and attitudes towards their current prostheses, and design priorities for an ideal transfemoral prosthesis, including the possibility of active assistance from a robotic knee unit. The survey was custom-developed based on several standard questionnaires used to assess motor abilities and autonomy in activities of daily living, prosthesis satisfaction, and quality of life in lower-limb amputees. Survey data were analyzed to compare the experience (including autonomy and satisfaction) and design priorities of users of transfemoral prostheses with versus without microprocessor-controlled knee units (MPKs and NMPKs, respectively), with a subsequent analyses of cross-category correlation, principal component analysis (PCA), cost-sensitivity segmentation, and unsupervised K-means clustering applied within the most cost-sensitive participants, to identify functional groupings of users with respect to their design priorities. RESULTS: The cohort featured predominantly younger (< 50 years) traumatic male amputees with respect to the general transfemoral amputee population, with pronounced differences in age distribution and amputation etiology (traumatic vs. non-traumatic) between MPK and NMPK groups. These differences were further reflected in user experience, with MPK users reporting significantly greater overall functional autonomy, satisfaction, and sense of prosthesis ownership than those with NMPKs, in conjunction with a decreased incidence of instability and falls. Across all participants, the leading functional priorities for an ideal transfemoral prosthesis were overall stability, adaptability to variable walking velocity, and lifestyle-related functionality, while the highest-prioritized general characteristics were reliability, comfort, and weight, with highly variable prioritization of cost according to reimbursement status. PCA and user clustering analyses revealed the possibility for functionally relevant groupings of prosthesis features and users, based on their differential prioritization of these features—with implications towards prosthesis design tradeoffs. CONCLUSIONS: This study’s findings support the understanding that when appropriately prescribed according to patient characteristics and needs in the context of a proactive rehabilitation program, advanced transfemoral prostheses promote patient mobility, autonomy, and overall health. Survey data indicate overall stability, modularity, and versatility as key design priorities for the continued development of transfemoral prosthesis technology. Finally, observed associations between prosthesis type, user experience, and attitudes concerning prosthesis ownership suggest both that prosthesis characteristics influence device acceptance and functional outcomes, and that psychosocial factors should be specifically and proactively addressed during the rehabilitation process. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12984-021-00944-x

Pseudolesions in cirrhotic liver

This chapter analyses the different benign liver lesions and pseudolesions occurring in cirrhotic livers, such as regenerative nodules (RNs), siderotic nodules (SNs), nodular regenerative hyperplasia (NRH), large regenerative nodules (LRNs), perfusion defects and trasient hepatic attenuetion difference (THAD)/transient hepatic attenuation difference (THID), hemangiomas in a cirrothic liver, pseudomass in chronic portal vein thrombosis (PVT), confluent fibrosis and focal fatty changes, such as focal steatosis and fat sparing, focusing on imaging features helpful in achieving a correct diagnosis

Significato del reversed halo sign nei pazienti oncoematologici con neutropenia e febbre

Il presente studio ha lo scopo di valutare la specificit\ue0 del reversed halo sign (RHS) in pazienti oncoematologici neutropenici febbrili e di esaminare il RHS in relazione allo stato immunitario

TC TORACE LOW-DOSE IN PAZIENTI EMATOLOGICI NEUTROPENICI FEBBRILI: COMPARAZIONE CON RX TORACE

Scopo Valutare l\u2019accuratezza di esami TC torace low-dose (LDCT) rispetto a RX torace nella valutazione di complicanze polmonari in pazienti ematologici con febbre antibiotico resistente. Materiale e metodi \uc8 stato svolto uno studio prospettico monocentrico, sono stati arruolati 50 pazienti ematologici febbrili ad alto rischio (BOscore &gt;5) per patologia fungina invasiva polmonare che sono stati sottoposti a RX torace e LDCT (100 kV; 30 mAs) entro 48 ore dall\u2019esordio febbrile. Una TC a dose standard (SDCT) eseguita sui reperti patologici della LDCT \ue8 stata usata come riferimento. Due radiologi con differente esperienza, non informati dei dati clinici dei pazienti, hanno analizzato indipendentemente gli esami RX e LDCT. Sono stati valutati l\u2019accordo interosservatore (Kappa di Cohen), il risultato diagnostico di RX e LDCT ed i dati dosimetrici. Risultati L\u2019accordo inter-osservatore \ue8 stato basso per le indagini RX (kappa: 0,367) ed alto (kappa: 0,925) per le indagini LDCT.Gli RX hanno dimostrato un risultato diagnostico scarso, lievemente migliorato dall\u2019esperienza (sensibilit\ue0: 40 vs 51 %; specificit\ue0 29 vs 54%; PPV: 41 vs 57%; VPN: 29 vs 48% per il radiologo non esperto rispetto all\u2019esperto). Le indagini LDCT hanno mostrato un alto rendimento diagnostico (entrambi i radiologi hanno individuato il 100% dei reperti LDCT), con differenze interpretative legate all\u2019esperienza.La dose misurata per gli esami LDCT \ue8 stata di 0,75\ub10,15 mSv (vs 0,1 mSv per gli RX), corrispondente a circa 7/8 RX. Conclusioni Il rendimento diagnostico LDCT \ue8 pi\uf9 alto delle indagini RX nello studio delle complicanze polmonari in pazienti ematologici ad alto rischio con febbre antibiotico resistente, ed \ue8 ragionevole utilizzare indagini LDCT al posto di RX come sistema di screening maggiormente accurato

Finite element modeling of an energy storing and return prosthetic foot and implications of stiffness on rollover shape

Energy storing and return (ESAR) prosthetic feet showed continuous improvements during the last 30 years. Despite this, standard guidelines are still missing to achieve an optimal foot design in terms of performances. One of the most important design parameters in ESAR feet is the Rollover Shape (RoS). This represents the foot Center of Pressure (CoP) path in a shank-based coordinate system during stance. RoS objectively describes the foot behavior according to its stiffness, which depends on foot geometry and material. This work presents the development of a finite element modeling methodology able to predict the stiffness characteristic of an ESAR foot and its RoS. The validation of the model is performed on a well-known commercially available prosthetic foot both in bench tests and realistic walking scenario. The obtained results confirm an error of +6.1% on stiffness estimation and +10.2% on RoS evaluation, which underlines that the proposed method is a powerful tool able to replicate the mechanical behavior of a prosthetic foot

Non-invasive tests for the prediction of post-hepatectomy liver failure in the elderly

Post-hepatectomy liver failure (PHLF) is associated with great morbidity and mortality after resection of hepatocellular carcinoma. Previous studies have underlined that advanced age could be a potential factor influencing post-operative complications and long-term survival.In the past, candidates for resection were based on the Child-Pugh classification, the predictive value of which was rather low. The selection of patients undergoing resection in Western countries is based on the assessment of portal hypertension (PH), which is clinically assessed by measurement of the hepatic venous pressure gradient, an invasive and costly process. Thus, there have been several attempts to identify the best non-invasive test (NIT) to accurately predict PHLF. Most biochemical NITs for the prediction of PHLF are focused on evaluation of underlying liver cirrhosis and PH. Amongst them, FIB-4, which also includes the patient’s age, seems to have more robust supporting results. In Europe and the USA., the most tested and reliable NIT for predicting PHLF is the evaluation of liver stiffness measurement, which is also influenced by age. Imaging parameters are promising tools which are used only in specialized centers however, and when available. Liver volume parameters, as well as contrast-enhanced data, demonstrate good accuracy in predicting PHLF. In this scenario, the evaluation of sarcopenia and bone mineral density through contextual imaging allows the delineation of PHLF in at-risk elderly patients. Further studies focused on parameters for the evaluation of PHLF in elderly patients are needed

Non-invasive tests for the prediction of post-hepatectomy liver failure in the elderly

Post-hepatectomy liver failure (PHLF) is associated with great morbidity and mortality after resection of hepatocellular carcinoma. Previous studies have underlined that advanced age could be a potential factor influencing post-operative complications and long-term survival. In the past, candidates for resection were based on the Child-Pugh classification, the predictive value of which was rather low. The selection of patients undergoing resection in Western countries is based on the assessment of portal hypertension (PH), which is clinically assessed by measurement of the hepatic venous pressure gradient, an invasive and costly process. Thus, there have been several attempts to identify the best non-invasive test (NIT) to accurately predict PHLF. Most biochemical NITs for the prediction of PHLF are focused on evaluation of underlying liver cirrhosis and PH. Amongst them, FIB-4, which also includes the patient\u2019s age, seems to have more robust supporting results. In Europe and the USA., the most tested and reliable NIT for predicting PHLF is the evaluation of liver stiffness measurement, which is also influenced by age. Imaging parameters are promising tools which are used only in specialized centers however, and when available. Liver volume parameters, as well as contrastenhanced data, demonstrate good accuracy in predicting PHLF. In this scenario, the evaluation of sarcopenia and bone mineral density through contextual imaging allows the delineation of PHLF in at-risk elderly patients. Further studies focused on parameters for the evaluation of PHLF in elderly patients are needed

Validation of a standardized CT protocol for the evaluation of varices and porto-systemic shunts in cirrhotic patients.

PURPOSE The aim of the present study was to propose and validate a standardized CT protocol for evaluating all the types of portosystemic collaterals (P-SC), including gastroesophageal varices and spontaneous portosystemic shunts (SPSS), and to evaluate the prognostic role of portal hypertension CT features for the prediction of the hepatic decompensation risk in cirrhotic patients. METHODS A retrospective cohort study of 184 advanced chronic liver disease who underwent CT scan between January 2014 and December 2017. Patients with an interval > 6 months between the imaging, elastometric, endoscopic and biochemical evaluation were excluded, as well as patients with previous transjugular intrahepatic portosystemic shunt (TIPS), liver transplantation (LT) or terminal medical conditions. Data on liver disease history, co-morbidities, endoscopic and radiologic findings were collected. The incidence of hepatic decompensation and other events, such as portal vein thrombosis, HCC, TIPS placement, LT, death, and its cause, were also recorded. The procedure was performed at baseline and after the administration of contrast agent using a multiphasic technique and bolus tracking. Two senior radiologists working in different centres and a non-expert radiologist reviewed all CT examinations, to evaluate both intra-observer and inter-observer variability of the CT protocol and to obtain an external validation. The radiological variables were evaluated using both univariate and adjusted multivariate competing risk regression models. RESULTS Both intra-observer and inter-observer agreement were excellent in detection and measurement of almost all types of P-SC. The presence of SPSS, a spleen diameter > 16 cm, a portal vein diameter > 17 mm and the presence of ascites resulted independent predictors of decompensation-free survival for cirrhotic patients and were incorporated in an easy-to-use score (AUROC = 0.799, p-value = 0.732) which can the risk of decompensation at 5 years, ranking it as low (11.3%), moderate (35.6%) or high (70.8%). CONCLUSIONS The CT protocol commonly performed during the HCC surveillance program for cirrhotic patients is valid for detecting all types of P-SC. The radiological score identified to predict the decompensation-free survival for cirrhotic patients could be an easy-to-use clinical tool