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Minimally invasive double-level osteotomy (DLP) surgery is performed in severe knee varus, when extra-articular deformity is identified in both the distal femur and proximal tibia. The main advantage is to maintain a horizontal joint line and avoid creating secondary anatomic deformities. This article considers the pearls and pitfalls in performing minimally invasive DLO surgery. [Display omitted] [ABSTRACT FROM AUTHOR]

Objectives: We hypothesize that chondrocytes from the deepest articular cartilage layer are pivotal in maintaining cartilage integrity and that the modification of their prehypertrophic phenotype to a hypertrophic phenotype will drive cartilage degradation in osteoarthritis.Design: Murine immature articular chondrocytes (iMACs) were successively cultured into three different culture media to induce a progressive hypertrophic differentiation. Chondrocyte were phenotypically characterized by whole-genome microarray analysis. The expression of IL-34 and its receptors PTPRZ1 and CSF1R in chondrocytes and in human osteoarthritis tissues was assessed by RT-qPCR, ELISA and immunohistochemistry. The expression of bone remodeling and angiogenesis factors and the cell response to IL-1β and IL-34 were investigated by RT-qPCR and ELISA.Results: Whole-genome microarray analysis showed that iMACs, prehypertrophic and hypertrophic chondrocytes each displayed a specific phenotype. IL-1β induced a stronger catabolic effect in prehypertrophic chondrocytes than in iMACs. Hypertrophic differentiation of prehypertrophic chondrocytes increased Bmp-2 (95%CI [0.78; 1.98]), Bmp-4 (95%CI [0.89; 1.59]), Cxcl12 (95%CI [2.19; 5.41]), CCL2 (95%CI [3.59; 11.86]), Mmp 3 (95%CI [10.29; 32.14]) and Vegf mRNA expression (95%CI [0.20; 1.74]). Microarray analysis identified IL-34, PTPRZ1 and CSFR1 as being strongly overexpressed in hypertrophic chondrocytes. IL-34 was released by human osteoarthritis cartilage; its receptors were expressed in human osteoarthritis tissues. IL-34 stimulated CCL2 and MMP13 in osteoblasts and hypertrophic chondrocytes but not in iMACs or prehypertrophic chondrocytes.Conclusion: Our results identify prehypertrophic chondrocytes as being potentially pivotal in the control of cartilage and subchondral bone integrity. Their differentiation into hypertrophic chondrocytes initiates a remodeling program in which IL-34 may be involved. [ABSTRACT FROM AUTHOR]

Objective: Avocado-Soybean Unsaponifiables (ASU) represent one of the most commonly used drugs for symptomatic osteoarthritis (OA). The mechanisms of its activities are still poorly understood. We investigate here the effects of ASU on signaling pathways in mouse or human chondrocytes.Methods: Mouse or human chondrocytes stimulated with interleukin-1beta (IL1beta, 10 ng/ml) and cartilage submitted to a compressive mechanical stress (MS) were studied in the presence or absence of ASU (10 microg/ml). Nuclear factor kappaB (NF-kappaB) activation was assessed by immunoblot, using an I-kappa B alpha antibody, nuclear translocation of NF-kappaB using p65 antibody, and extra-cellular signal-regulated kinase (ERK)1/2 activation using phospho and ERK1/2 antibodies. The binding of the p50/p65 complex on DNA was studied by electrophoretic mobility shift assay.Results: ASU decrease matrix metalloproteinases-3 and -13 expressions and Prostaglandin E(2) (PGE(2)) release in our model. The degradation of I-kappa B alpha is prevented in the presence of ASU as shown by the persistent expression of I-kappa B alpha protein in the cytosol when chondrocytes are stimulated by IL1beta or MS. Nuclear translocation of the NF-kappaB complex is shown by the decrease of the p65 protein from the cytosol, whereas p65 appears in the nucleus under IL1beta stimulation. This translocation is abolished in the presence of ASU. Moreover, bandshift experiments show an inhibition of the IL1beta-induced binding of p50/p65 complexes to NF-kappaB responsive elements in response to ASU. Finally, among the different mitogen-activated protein kinases known to be induced by IL1beta, ERK1/2 was the sole kinase inhibited by ASU.Conclusion: These results demonstrate that ASU express a unique range of activities, which could counteract deleterious processes involved in OA, such as inflammation. [ABSTRACT FROM AUTHOR]

Summary Objective To examine the relationship between osteoarthritis (OA) and type 2 diabetes mellitus (DM). Methods OA cartilage from DM and non-DM patients undergoing knee replacement were stimulated by IL-1β for 24 h and release of interleukin-6 (IL-6) and prostaglandin E 2 (PGE 2 ) was measured. Primary cultured murine chondrocytes were stimulated for 24 and 72 h with or without IL-1β (5 ng/mL) under normal-glucose (5.5 mM) or high-glucose (25 mM) conditions. The expression and release of pro-inflammatory mediators (IL-6, cyclooxygenase 2 [COX2]/PGE 2 ) were analyzed by quantitative RT-PCR and ELISA/EIA. Glucose uptake was assessed with ( 14 C)-2-deoxyglucose. Reactive oxygen species (ROS) and nitric oxide (NO) production were measured. To analyze the mechanism of IL-1β-induced inflammation, cells were pretreated or treated with inhibitors of glucose transport (cytochalasin B), the polyol pathway (epalrestat), mitochondrial oxidative stress (MitoTEMPO) or nitric oxide synthase ( l -NAME). Results With IL-1β stimulation, IL-6 and PGE 2 release was greater in human DM than non-DM OA cartilage (2.7- and 3-fold, respectively) ( P < 0.05). In vitro , with IL-1β stimulation, IL-6 and COX2 mRNA expression, IL-6 and PGE 2 release, and ROS and NO production were greater under high-than normal-glucose conditions in cultured chondrocytes. IL-1β–increased IL-6 release was reduced with cytochalasin B, epalrestat, l -NAME or MitoTEMPO treatment (−45%, −62%, −38% and −40%, respectively). Conclusion OA cartilages from DM patients showed increased responsiveness to IL-1β–induced inflammation. Accordingly, high glucose enhanced IL-1β–induced inflammation in cultured chondrocytes via oxidative stress and the polyol pathway. High glucose and diabetes may thus participate in the increased inflammation in OA. [ABSTRACT FROM AUTHOR]

The evolution of anti-pollution standards and the optimization of combustion efficiency push the development of new fuels with high energy efficiency. It is necessary to develop new alternative fuel to improve the efficiency of conventional systems, reduce emissions (NO x , SO x , soot particles) and recover for its materials. A new fuel called bio-hythane, a mixture of natural gas up to 20% hydrogen and up to 50% Carbone dioxide, from the recovery of the waste from households and agriculture, via suitable digesters provides a source of renewable energy and usable, is a very interesting solution to improve emission standards and optimization of the combustion chambers. This experimental study is led in a non-reacting configuration and in combustion in order to focus on the effects of hydrogen addition and CO 2 dilution in the fuel on the velocity profiles, the turbulence intensity and the turbulent kinetic energy. From PIV measurements the results show that from the velocity and fluctuations profiles the high diffusivity and the low density of hydrogen allow bio-hythane jet to spread more efficiency in the combustion. The combustion decreases the entrainment of the ambient fluid and raises the viscosity of the flow, leading to an increase of the longitudinal velocity along the bio-hythane jet and a reduction of the turbulence in comparison with non-reacting configuration. The Carbone dioxide addition reduces the fall of the turbulence because the temperature of the flame is less important. Effects of hydrogen and CO 2 are also highlighted by analysis of turbulent kinetic energy along the bio-hythane. [ABSTRACT FROM AUTHOR]

Abstract: In this work we present a multiscale theoretical methodology that scales up ab initio calculated data into elementary kinetic models in order to simulate Polymer Electrolyte Membrane Fuel Cells (PEMFC) transient operation. Detailed Density Functional Theory (DFT) calculations are performed on a model Pt(111) surface to determine the elementary kinetic rates of the Oxygen Reduction Reaction (ORR) mechanism at a Pt-based PEMFC cathode. These parameters include the effect of surface coverage on the activation barriers and are implemented into a Mean Field model describing the behavior of the electric field and charge distribution at the nanoscale interfacial vicinity to the catalyst, which is in turn coupled with microscale and mesoscale level models describing the charge and reactants and water transport phenomena across the cell. The impact of two possible ORR mechanisms on the simulated i–V curves is investigated: a first route connected with the dissociative adsorption of molecular oxygen on Pt(111), a second route related to the formation and the transformation of OOH surface species. The similarities and differences of the associated calculated i–V responses for each of these routes and the consequences on the interpretation of electrochemical observables at the cell level are discussed. [Copyright &y& Elsevier]

Abstract: The active control of oxy-fuel flames from burners with separated jets is investigated. The control system consists of four small jet actuators, placed tangential to the exit of the main jets to generate a swirling flow. These actuators are able to modify the flow structure and to act on mixing between the reactants and consequently on the flame behavior. The burner (25kW) is composed of separated jets, one jet of natural gas and one or two jets of pure oxygen. Experiments are conducted with three burner configurations, according to the number of jets, the jet exit velocities, and the separation distance between the jets. OH chemiluminescence measurements, particle image velocimetry, and measurements of NO x emissions are used to characterize the flow and the flame structure. Results show that the small jet actuators have a significant influence on the behavior of jets and the flame characteristics, particularly in the stabilization zone. It is shown that the control leads to a decrease in lift-off heights and to better stability of the flame. The use of jet actuators induces high jet spreading and an increase in turbulence intensity, which improves the mixing between the reactants and the surrounding fluid. Pollutant measurements show important results in terms of NO x reductions (up to 60%), in particular for low swirl intensity. The burner parameters, such as the number of jets and the spacing between the jets, also impact the flame behavior and NO x formation. [Copyright &y& Elsevier]

Abstract: The effect of solid particles on the flow characteristics of axisymmetric turbulent coaxial jets for two flow conditions was studied. Simultaneous measurements of size and velocity distributions of continuous and dispersed phases in a two-phase flow are presented using a Phase Doppler Anemometry (PDA) technique. Spherical glass particles with a particle diameter range from 102 to 212μm were used in this two-phase flow, the experimental results indicate a significant influence of the solid particles and the Re on the flow characteristics. The data show that the gas phase has lower mean velocity in the near-injector region and a higher mean velocity at the developed region. Near the injector at low Reynolds number (Re=2839) the presence of the particles dampens the gas-phase turbulence, while at higher Reynolds number (Re=11893) the gas-phase turbulence and the velocity fluctuation of particle-laden jets are increased. The particle velocity at higher Reynolds number (Re=11893) and is lower at lower Reynolds number (Re=2839). The slip velocity between particles and gas phase existed over the flow domain was examined. More importantly, the present experiment results suggest that, consideration of the gas characteristic length scales is insufficient to predict gas-phase turbulence modulation in gas-particle flows. [Copyright &y& Elsevier]

Abstract: Oxy-fuel combustion in separated-jet burners has been proven to increase thermal efficiency and to have a potential for NOx emission reduction. This paper presents an investigation into confined, turbulent, oxy-flames generated by a burner consisting of a central natural gas jet surrounded by two oxygen jets. The study is focused on the identifying the influence of burner parameters on the flame characteristics and topology, namely stability, lift-off height and flame length. The effects of the natural gas and oxygen jet exit velocities, the distance separating the jets and the deflection of oxygen jets towards the natural gas jet are examined. The OH chemiluminescence. Results show that the lift-off heights increase when jet exit velocities and the distance separating the jets are increased. The deflection of oxygen jets decreases the lift-off height and increases the volume of flame in the transversal plane. The flame length increases principally with the oxygen exit velocity and the separation distance, and decreases considerably when the angle of oxygen jets is increased. [Copyright &y& Elsevier]

Purpose: The aims of this radiologic study were to explore the anatomic aspect of the external third of the clavicle and to determine anatomic elements that can be useful for surgeons who perform surgery that involves this area. Methods: Twenty patients with healthy acromioclavicular (AC) joints underwent computed tomographic (CT) scan for assessment of the lateral clavicle. Three-dimensional reconstruction of the AC joint and of the external third of the clavicle was performed. The axis of the external third was determined by CT scan reconstruction. Two-dimensional reconstructions were performed perpendicular to this axis; each involved 5 mm for exploration of the size of the 4 cortical bones and of the inner diameter of the clavicle. Results: The average size of the external third before the anterior curve of the clavicle was 40 mm. The average inner diameter of the clavicle ranged from 8.24 to 4.7 mm when measured medially, but many differences were noted between patients. The upper cortical bone was thicker than 2 mm at an average of 17 mm from the AC joint. Three forms of the external third of the clavicle were identified: truncated (n = 6), conical (n = 4), and cylindrical (n = 10). The projection of the axis of the external third of the clavicle at the external side of the acromial bone ranged from 4.8 to 21 mm (average, 12.42 mm) at the backward anterior side of the acromial bone. Conclusions: Our study shows the great variability of the anatomy of the external third of the clavicle. Clinical Relevance: Anatomic data should be useful for surgeons who perform fixation or resection of the distal part of the clavicle. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to evaluate the arthroscopically assisted Bristow-Latarjet procedure. The aim was to use arthroscopic guidance to assist in positioning of the coracoid bone block onto the anterolateral aspect of the glenoid. The feasibility of this technique and its efficacy, reproducibility, and potential neurovascular complications were evaluated. Methods: A minimally invasive technique was used to harvest the coracoid bone block and the attached coracobiceps tendon. A portal was created through the subscapularis muscle and, under arthroscopic guidance, the anterior aspect of the glenoid was cleaned and reamed before the bone block was placed. Cannulated screws (3.5 mm) were used to fix the vertically oriented bone block to the glenoid. The size of the bone block, its position on the glenoid, and its relation to the subscapularis tendon and the musculocutaneous and axillary nerves were recorded. Results: In all 5 cadavers, the bone block was well positioned and was fixed to the anteroinferior part of the glenoid. No lesions of the cephalic vein or of the surrounding neurovasculature were observed. Conclusions: This study demonstrated the safe and effective use of this arthroscopically assisted technique for correct positioning of the coracoid bone block at the anterolateral aspect of the glenoid in the cadaveric shoulder. Arthroscopy facilitated adequate reaming of the anterior glenoid and aided in optimal positioning of the bone block. Clinical Relevance: This cadaveric study highlights the advantages offered by an arthroscopically assisted Bristow-Latarjet procedure, which optimizes positioning of the block and ensures adequate reaming of the anterior glenoid, thereby potentially reducing the risks of early nonunion and late arthritis—complications commonly associated with the classical Bristow-Latarjet technique. [Copyright &y& Elsevier]

This paper reports on the experimental and numerical results of the hythane diffusion flame enriched by oxygen, realized in a coaxial burner characterized by a central jet of hythane injection with an internal diameter of d fuel = 6 mm and an annular jet of oxidant injection with a diameter of d ox = 18 mm. For velocity measurements, the Particle Image Velocimetry (PIV) technology is used. The numerical study is based on the K-ω-SST Turbulent Model and the Eddy Dissipation Model (EDM) for combustion. Firstly, a comparative study is carried out between experimental and numerical simulation of the flow dynamics in the hythane/Air + O 2 flame. Secondly, the numerical results show that the oxygen enrichment increases the temperature of the hythane flame and minimizes the formation of harmful gases into the environment. • Oxygen enrichment favors the flame temperature and reduces the hythane flame length. • The oxygen enrichment reduces the total volume of combustion products. • The oxygen enrichment minimizes the carbon monoxide production. • The mixture fraction characterizes the mixture quality between reactants. [ABSTRACT FROM AUTHOR]

In this study, the NG + H 2 /air + O 2 turbulent flame is numerically investigated using the Computational Fluid Dynamics CFD code. The modulation of combustion and radiation is performed respectively by the Eddy Dissipation Model and the Discrete Ordinate Model. The turbulence modeling is carried out by Shear Stress Transport (SST/k-ω) turbulence model. The H 2 amount in the fuel mixture varies under constant volumetric fuel flow between 0 and 60% and the oxidant is composed by 80% air and 20% pure oxygen. The results obtained show the hydrogen addition to Natural Gas improves the mixing between the reactants, reduces their residence time and reduces the length and thickness of the flame. On the other hand, the hydrogen enrichment minimizes the CO 2 and CO production and increases the NO x level. • The hydrogen addition to fuel improves the mixing between the reactants and favors the flame temperature. • The hydrogen enrichment reduces the flame length and thickness. • The hydrogen addition minimizes the CO 2 and CO production and increases the NO x. [ABSTRACT FROM AUTHOR]

Fire behavior in a 1 m3 confined and mechanically ventilated compartment is investigated experimentally. The main objective is to study carbon monoxide and soot particle emissions by four different fuels: pure n-heptane, technical-grade dodecane, kerosene Jet A-1, and Mobil DTE oil heavy medium. Air Renewal rates are set at 4.83 ACH, 9.67 ACH, and 17.8 ACH, while the fuel pan diameters are 0.115 m, 0.14 m, and 0.19 m. The results show that decreasing the renewal rate or increasing the pan size decreases the mass loss rate and soot emissions. However, CO emissions increase. Lighter fuels exhibit higher mass loss rates and CO emissions than heavier fuels. The highest smoke temperatures are produced at high renewal rates and large pan diameters. Meanwhile, soot emission levels decrease in the order of kerosene > dodecane > Mobil oil > heptane. High levels of soot but low CO emissions are present in well-ventilated fires. However, high CO but low soot emissions appear in under-ventilated fires. The soot particles collected in the smoke layer show unimodal distribution. The modal diameter of the particles ranges from 220 nm to 300 nm. [ABSTRACT FROM AUTHOR]

Abstract: With regard to the anatomic basis of Neer type 2 fractures of the distal part of the clavicle, a clavicle fracture is associated with a coracoclavicular conoid ligament disruption. We describe an arthroscopic-assisted surgical procedure to stabilize the fracture and reconstruct the ligament. Surgery is performed with the patient in the beach-chair position. Through a 2-cm incision perpendicular to the direction of the fracture, we perform suturing around the fracture. During the arthroscopic procedure, the coracoid process is exposed by opening the rotator interval and the medial part of the capsule. The knee of the coracoid process should be exposed via an anterolateral portal for the arthroscope. Then, by use of an acromioclavicular joint stabilization device from Arthrex (Naples, FL), a hole is placed through the knee of the coracoid process. FiberTape suture (Arthrex) is passed around the clavicle and through the knee of the coracoid process. The intra-articular sutures are pulled out through the upper incision on top of the clavicle. Tightening of the 2 knots is performed at the same time. This arthroscopic-assisted surgery allows for total recovery of shoulder function, without the inconvenience of device migration or acromioclavicular joint lesions reported with other procedures. [Copyright &y& Elsevier]