Fibrin glue improves osteochondral scaffold fixation: study on the human cadaveric knee exposed to continuous passive motion

SummaryObjectiveTo evaluate stability and integrity of bi-layer and three-layer collagen-hydroxyapatite (C-HA) osteochondral scaffolds in a human cadaveric knee exposed to continuous passive motion (CPM) with and without loading and the role of added fibrin glue to improve the press-fit fixation of C-HA scaffolds.DesignOsteochondral lesions (2.0 × 1.5 cm) were chiseled out on both condyles and trochlea in eight human cadaveric knees. A total of 24 bi-layer (5 mm, four in each condyle) or three-layer C-HA scaffolds (8 mm, eight in the trochlea, four in each condyle) were first press-fit implanted and underwent testing with CPM, 90 cycles, 0°–90°. The second set of 24 scaffolds was implanted in cleaned lesions with the addition of fibrin glue. Two knees with fibrin glue fixation were additionally exposed to 15 kg loading, with 30 cycles of CPM, 0°–30°. Then, the knees were reopened and the scaffolds were evaluated using semi-quantitative Drobnic and modified Bekkers scores.ResultsAll but two scaffolds remained in the lesions site throughout CPM. Two implants failed: both were bi-layer osteochondral scaffolds, press-fit implanted at the lateral femoral condyle (LFC). A statistically significant difference was obtained between press-fit and fibrin glue implants with both Drobnic (2.9 ± 0.7 vs 4.3 ± 0.1, P < 0.0005) and Bekkers (3.3 ± 1.0 vs 5.0 ± 0.1, P < 0.0005) scores. Additional knee loading did not affect fibrin glue scaffold fixation or integrity.ConclusionThis cadaveric study showed fibrin glue notably improved bi-layer or three-layer C-HA scaffold press-fit fixation regardless of lesion location. It is therefore recommended that fibrin glue be used during surgery to improve early post-operative C-HA scaffold stability and integrity

Towards Predictive Maintenance for Flexible Manufacturing Using FIWARE

Industry 4.0 has shifted the manufacturing related processes from conventional processes within one organization to collaborative processes across different organizations. For example, product design processes, manufacturing processes, and maintenance processes across different factories and enterprises. This complex and competitive collaboration requires the underlying system architecture and platform to be flexible and extensible to support the demands of dynamic collaborations as well as advanced functionalities such as big data analytics. Both operation and condition of the production equipment are critical to the whole manufacturing process. Failures of any machine tools can easily have impact on the subsequent value-added processes of the collaboration. Predictive maintenance provides a detailed examination of the detection, location and diagnosis of faults in related machineries using various analyses. In this context, this paper explores how the FIWARE framework supports predictive maintenance. Specifically, it looks at applying a data driven approach to the Long Short-Term Memory Network (LSTM) model for machine condition and remaining useful life to support predictive maintenance using FIWARE framework in a modular fashion

Personality Traits in Miners with Past Occupational Elemental Mercury Exposure

In this study, we evaluated the impact of long-term occupational exposure to elemental mercury vapor (Hg(0)) on the personality traits of ex-mercury miners. Study groups included 53 ex-miners previously exposed to Hg(0) and 53 age-matched controls. Miners and controls completed the self-reporting Eysenck Personality Questionnaire and the Emotional States Questionnaire. The relationship between the indices of past occupational exposure and the observed personality traits was evaluated using Pearson’s correlation coefficient and on a subgroup level by machine learning methods (regression trees). The ex-mercury miners were intermittently exposed to Hg(0) for a period of 7–31 years. The means of exposure-cycle urine mercury (U-Hg) concentrations ranged from 20 to 120 μg/L. The results obtained indicate that ex-miners tend to be more introverted and sincere, more depressive, more rigid in expressing their emotions and are likely to have more negative self-concepts than controls, but no correlations were found with the indices of past occupational exposure. Despite certain limitations, results obtained by the regression tree suggest that higher alcohol consumption per se and long-term intermittent, moderate exposure to Hg(0) (exposure cycle mean U-Hg concentrations > 38.7 < 53.5 μg/L) in interaction with alcohol remain a plausible explanation for the depression associated with negative self-concept found in subgroups of ex-mercury miners. This could be one of the reason for the higher risk of suicide among miners of the Idrija Mercury Mine in the last 45 years

Liver hanging maneuver for right hemiliver in situ donation – anatomical considerations

Background. An anatomical study was carried out to evaluate the safety of the liver hanging maneuver for the right hemiliver in living donor and in situ splitting transplantation. During this procedure a 4–6 cm blind dissection is performed between the inferior vena cava and the liver. Short subhepatic veins entering the inferior vena cava from segments 1 and 9 could be torn with consequent hemorrhage. Materials and methods. One hundred corrosive casts of livers were evaluated to establish the position and diameter of short subhepatic veins and the inferior right hepatic vein. Results. The average distance from the right border of the inferior vena cava to the opening of segment 1 veins was 16.7±3.4 mm and to the entrance of segment 9 veins was 5.0±0.5 mm. The width of the narrowest point on the route of blind dissection was determined, with the average value being 8.7±2.3 mm (range 2–15 mm). Discussion. The results show that the liver hanging maneuver is a safe procedure. A proposed route of dissection minimizes the risk of disrupting short subhepatic veins (7%)

Anatomical variations in the pattern of the right hepatic veins: possibilities for type classification

A morphological study of the right hepatic veins (RHVv) was conducted based on the shape and the confluence pattern of the superior right hepatic vein (SRHV) and the presence of accessory right hepatic veins. The study was performed in 110 undamaged, randomly selected, cadaveric human livers prepared using the corrosion cast methodology. The principles for classifying the RHVv into types were as follows: the length of the vein trunk, the confluence of 2 or 3 main tributaries that form a trunk, and the accessory right hepatic veins that modify the venous drainage of the right side of the liver. Four types of SRHV were identified. Type 1 (20%), type 2 (40%) and type 3 (25%) were the most common, while type 4 (15%) was linked to the accessory right hepatic veins in cases where they drain a surgically important part of the liver. Accessory right hepatic veins were found in a total of 31 casts (28%). The hepatocaval confluence was studied and the tributary-free part of the SRHV trunk before it entered the inferior vena cava was measured. The tributary-free part of the SRHV was longer than 1 cm in 77% of the casts. Anastomoses between the terminal tributaries of the veins involved in the drainage of the right side of the liver were also investigated

A Methodological Approach for the Identification of Context-Specific Reconfiguration Options in the PLM-Context

Part 6: Product-Service Systems and Smart ProductsInternational audienceCurrent changes of traditional products towards intelligent, connected smart products require a fundamental adaption and enhancement of traditional Product Lifecycle Management approaches. In our previous activities we showed that lifecycle management approaches lack suitable methods and IT tools for smart products especially during their use phase. In particular the reconfiguration in the use phase has been addressed, as the characteristic properties of smart products enable a tremendous potential. As an approach virtual product twins were introduced in our previous activities in order to manage both virtual product models as well as product usage data across all engineering domains including environmental data. This contribution describes the core enabler, such as the reconfiguration lifecycle and virtual product twins for the reconfiguration of smart products during their use phase including the necessity of designing the architecture of reconfiguration options. The scope is the introduction of a methodological approach, which allows the identification of context-specific reconfiguration options

Improving the portability and exchangeability of model data for smart grids focusing on real-time simulations – definition of a common reference model

A key and important aspect of future power and energy systems is the integration of renewable and distributed energy resources. In order to develop, test and implement such distributed energy resources appropriate methods, procedures and guidelines are necessary. In 2009 a consortium of sixteen partners from industry and research started the DERri project (Distributed Energy Resources Research Infrastructures) to examine this issue. A special focus of the work in the DERi project is related to the improvement of simulation methods, with emphasis on the real-time domain, in order to support the development and implementation of DER devices. Currently no standardized modelling and simulation procedures as well as data formats for the exchange of realtime models exist; the DERri consortium has begun work on developing suitable exchange mechanisms. This paper presents and examines an approach to providing a standards-based model representation, especially for the real-time simulation of distributed energy resource devices. The main aim of this concept is the improvement of the exchange of model information and results from offline and realtime simulations between different research groups. A major result of this approach is the so called Common Reference Model for distributed energy resource components