Development of a Passive and Slope Adaptable Prosthetic Foot

Historically, users of prosthetic ankles have relied on actively operated systems to provide effective slope adaptability. However, there are many drawbacks to these systems. This research builds upon work previously completed by Hansen et al. as it develops a passive, hydraulically operated prosthetic ankle with the capability of adapting to varying terrain in every step. Using gait cycle data and an analysis of ground reaction forces, the team determined that weight activation was the most effective way to activate the hydraulic circuit. Evaluations of the system pressure and energy showed that although the spring damper system results in a loss of 9J of energy to the user, the footplate stores 34J more than a standard prosthesis. Therefore, the hydraulic prosthetic provides a 54% increase in stored energy when compared to a standard prosthesis. The hydraulic circuit manifold prototype was manufactured and tested. Through proof of concept testing, the prototype proved to be slope adaptable by successfully achieving a plantarflexion angle of 16 degrees greater than a standard prosthetic foot currently available on the market.Massachusetts Institute of Technology. Tata Center for Technology and Desig

Oliksidig krympning i betong

Betong är ett av de vanligaste använda byggmaterialen vid uppförande av grund och stomme. Betongens egenskaper gör den mycket tålig för yttre påfrestningar och därav gör den till ett mycket användbart material i många olika situationer. Det finns dock problem som kan uppstå vid användandet av betong. Ett av de vanligare är sprickbildning. Det finns flera orsaker till att detta förekommer, till exempel yttre påverkan, krypning, temperatur- och fuktrelaterade rörelser. Betongplattan är en av de konstruktionsdelar som utsätts oftast för detta problem. Då plattan används frekvent som grundkonstruktion finns i intresse att hitta åtgärder för detta, men då måste orsakerna specificeras tydligare. I denna studie undersöks experimentellt hur en betongplatta reagerar när olika fukthalter råder på ovan- och undersida efter härdningsperioden, och om detta kan bidra till tillräckliga deformationer för att orsaka sprickbildning. 6 prover har gjutits och observerats där 3st har utsatts för ett simulerat markupplagsförhållande där en fukthalt på 100% har exponerat undersidan. De resterande 3 proverna har placerats i torra förhållanden för att göra jämförelser möjliga. En relativ ånghalt på 25% har varit aktuell i den omgivande luften. Experimentet visade på tydliga skillnader i deformation mellan de olika upplagen. De prover som utsatts för det fuktigare förhållandet uppvisade tillräcklig krökning för att orsaka sprickbildning sett utifrån det moment som uppstod i betongen. Detta tyder på att olika rådande fukthalter på ovan- och undersida av en betongplatta kan skapa tillräckliga påfrestningar för att orsaka sprickbildning.Concrete is one of the most commonly used building materials in foundation construction. Concrete is highly resistant to external stresses and hence makes it a very useful material in many different situations. However, there are problems that can arise with the use of concrete. One of the more common is cracking. There are several reasons why this might occur, for example, external impact, creep and moist-related movements. The concrete slab is one of the elements that often encounter this problem. Since concrete slabs are frequently used as foundation, it is of great interest to find solutions for this matter. In order to do that, the causes are needed to be specified more clearly. This study investigated experimentally how a concrete slab reacts when differences in humidity exposing the top and bottom after curing period, and if this may contribute to sufficient deformation to cause cracking. Six specimens were made and observed where three where exposed to a moisture content of 100% on the bottom. The remaining three samples have been placed in dry conditions in order to make a comparison possible. A relative humidity of 25% was measured in the surrounding air. The experiment showed clear differences in deformation between the two situations. The samples exposed to differential humidity exhibited sufficient stresses to cause cracking seen from the moment that occurred in the concrete. This shows that different prevailing humidity on the top and bottom of a slab can create sufficient stress to cause cracking

Estimate of hepatocellular carcinoma incidence in patients with alcoholic cirrhosis

International audienceBACKGROUND & AIMS: More than 90% of cases of hepatocellular carcinoma (HCC) occur in patients with cirrhosis, of which alcohol is a major cause. The CIRRAL cohort aimed to assess the burden of complications in patients with alcoholic cirrhosis, particularly the occurrence of HCC.METHODS: Patients with biopsy-proven compensated alcoholic cirrhosis were included then prospectively followed. The main endpoint was the incidence of HCC. Secondary outcomes were incidence of hepatic focal lesions, overall survival (OS), liver-related mortality and event-free survival (EFS).RESULTS: From October 2010 to April 2016, 652 patients were included in 22 French and Belgian centers. During follow-up (median 29 months), HCC was diagnosed in 43 patients. With the limitation derived from the uncertainty of consecutive patients' inclusion and from a sizable proportion of dropouts (153/652), the incidence of HCC was 2.9 per 100 patient-years, and one- and two-year cumulative incidences of 1.8% and 5.2%, respectively. Although HCC fulfilled the Milan criteria in 33 cases (77%), only 24 patients (56%) underwent curative treatment. An explorative prognostic analysis showed that age, male gender, baseline alpha-fetoprotein, bilirubin and prothrombin were significantly associated with the risk of HCC occurrence. Among 73 deaths, 61 had a recorded cause and 27 were directly attributable to liver disease. At two years, OS, EFS and cumulative incidences of liver-related deaths were 93% (95% CI 90.5-95.4), 80.3% (95% CI 76.9-83.9), and 3.2% (95% CI 1.6-4.8) respectively.CONCLUSION: This large prospective cohort incompletely representative of the whole population with alcoholic cirrhosis showed: a) an annual incidence of HCC of up to 2.9 per 100 patient-years, suggesting that surveillance might be cost effective in these patients; b) a high proportion of HCC detected within the Milan criteria, but only one-half of detected HCC cases were referred for curative treatments; c) a two-year mortality rate of up to 7%

Albumin Use in Patients With Cirrhosis in France: Results of the “ALBU-LIVE” Survey

International audienceIntroductionThe use of human albumin for the management of cirrhosis has increased. Recommendations have been published for therapeutic paracentesis (TP), spontaneous bacterial peritonitis (SBP), and type 1 hepatorenal syndrome (HRS). The goal of this survey was to assess the prescription practices of French hepatogastroenterologists.MethodsAll hepatogastroenterologists were contacted. The questionnaire evaluated (1) the use of albumin in validated indications and (2) the prescription of albumin for nonvalidated clinical situations.ResultsResponses were analyzed from 451 (50.1%) practitioners. The mean age was 40 years (range, 24 to 67 y). Physicians practiced in a university hospital (47.7%) or a general hospital (45.8%). There were 56.7% senior practitioners. Overall 99.6% of the practitioners compensated for TP. Albumin was used by 87.8% of the physicians, with a fixed dose being used by 84.6%. For SBP, 94% of the physicians used albumin concomitantly with antibiotics. The recommended protocol was followed by 56.2% of the practitioners: more often by senior university hospital practitioners than by senior general hospital practitioners (P=0.015). About 66.5% used albumin infusion for the diagnosis of HRS: used more often by senior university hospital practitioners (P=0.0006). Albumin was used concomitantly with vasopressor treatment by 84%; the dose and the duration varied considerably. About 23.5% used albumin for severe bacterial infection, 47.9% for severe hyponatremia, 43.9% for severe hypoalbuminemia, and 65.9% for hydrothorax.ConclusionsIn this large French survey, albumin is only prescribed in accordance with recommendations for TP. The schedule for SBP is followed by only 56% of the practitioners. The use of albumin for HRS is not adapted to recommendations, which are not well known, suggesting that they should be more diffused

Inserting pedicle screws in the upper thoracic spine without the use of fluoroscopy or image guidance. Is it safe?

Several studies have looked at accuracy of thoracic pedicle screw placement using fluoroscopy, image guidance, and anatomical landmarks. To our knowledge the upper thoracic spine (T1–T6) has not been specifically studied in the context of screw insertion and placement accuracy without the use of either image guidance or fluoroscopy. Our objective was to study the accuracy of upper thoracic screw placement without the use of fluoroscopy or image guidance, and report on implant related complications. A single surgeon inserted 60 screws in 13 consecutive non-scoliotic spine patients. These were the first 60 screws placed in the high thoracic spine in our institution. The most common diagnosis in our patient population was trauma. All screws were inserted using a modified Roy-Camille technique. Post-operative axial computed tomography (CT) images were obtained for each patient and analyzed by an independent senior radiologist for placement accuracy. Implant related complications were prospectively noted. No pedicle screw misplacement was found in 61.5% of the patients. In the remaining 38.5% of patients some misplacements were noted. Fifty-three screws out of the total 60 implanted were placed correctly within all the pedicle margins. The overall pedicle screw placement accuracy was 88.3% using our modified Roy-Camille technique. Five medial and two lateral violations were noted in the seven misplaced screws. One of the seven misplaced screws was considered to be questionable in terms of pedicle perforation. No implant related complications were noted. We found that inserting pedicle screws in the upper thoracic spine based solely on anatomical landmarks was safe with an accuracy comparable to that of published studies using image-guided navigation at the thoracic level

ABO blood group does not influence Child‐Pugh A cirrhosis outcome: An observational study from CIRRAL and ANRS CO12 CIRVIR cohorts

International audienceBackground and aims: Non-O blood group promotes deep vein thrombosis and liver fibrosis in both general population and hepatitis C. We aimed to evaluate the influence of Non-O group on the outcome of Child-Pugh A cirrhotic patients.Methods: We used two prospective cohorts of Child-Pugh A cirrhosis due to either alcohol or viral hepatitis. Primary end point was the cumulated incidence of 'Decompensation' at 3 years, defined as the occurrence of ascites , hydrothorax, encephalopathy, gastrointestinal bleeding related to portal hypertension, or bilirubin >45 μmol/L. Secondary end points were the cumulated incidences of (1) 'Disease Progression' including a « decompensation» or « the occurrence of one or more parameters » among: prothrombin time (PT) <45%, albumin <28 g/L, Child-Pugh worsening (B or C vs A or B, C vs B), hepatorenal syndrome, and hepato-pulmonary syndrome, (2) other events such as non-malignant portal vein thrombosis (nmPVT), and (3) overall survival.Results: Patients (n = 1789; 59.9% Non-O group; 40.1% group O) were followed during a median of 65.4 months. At 3 years cumulated incidence of Decompensation was 8.3% in Non-O group and 7.2% in group O (P = .27). Cumulated incidence of Disease Progression was 20.7% in Non-O group and 18.9% in group O (P = .26). Cumulated incidence of nmPVT was 2.7% in Non-O group and 2.8% in group O (P = .05). At 3 years overall survival was 92.4% in Non-O group and 93.4% in group O (P = 1).Conclusion: Non-O group does not influence disease outcome in Child-Pugh A cirrhotic patients. Clinicals trial number NCT03342170