French expert group proposal for lipid-lowering therapy in the first 3 months after acute myocardial infarction

In patients admitted for acute myocardial infarction (MI), it has been demonstrated that reducing LDL cholesterol (LDL-c) is associated with a reduction in major adverse cardiovascular events. We describe a consensual proposal made by a French group of experts for lipid-lowering therapy at the acute phase of acute myocardial infarction. A group of French experts comprising cardiologists, lipidologists and general practitioners prepared a proposal for a lipid-lowering strategy with a view to optimizing LDL-c levels in patients hospitalized for myocardial infarction. We describe a strategy for the use of statins, ezetimibe and and/or proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors, with a view to reaching target LDL-c levels as early as possible. This approach, which is currently feasible in France, could considerably improve lipid management in patients after ACS, thanks to its simplicity, rapidity and the magnitude of the decrease in LDL-c that it achieves.

Lipid-lowering treatment up to one year after acute coronary syndrome: guidance from a French expert panel for the implementation of guidelines in practice

The management of patients with coronary artery disease (CAD) is complex, especially after they have been discharged from hospital after an acute coronary syndrome (ACS), because each patient may have numerous healthcare providers, and follow-up after discharge may be disjointed, or even incomplete. During follow-up after ACS, few patients have treatment intensification; rather, there is actually a major tendency towards reductions in treatment intensity, to the potential detriment of outcomes. We present here guidance from a French expert panel for the optimal management of lipid-lowering therapy up to 1 year after ACS. A French expert panel provides a practical guide for the implementation of guidelines for the management of post-ACS patients in routine practice, from hospital discharge up to one year after the index event, focusing in particular on the achievement of target LDL cholesterol (LDL-C) levels. We discuss the early follow-up (up to 6 months after discharge) and review the lipid-lowering treatment strategies that should be implemented. We discuss the evidence underpinning the prescription of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors as well as recent evidence about icosapent ethyl. This review should facilitate implementation of a clear and effective lipid-lowering strategy for all patients after ACS. The panel recommends early use of high-intensity statins, in combination with ezetimibe for patients with LDL-c above 100 mg/dL at baseline. PCSK9i should be rapidly added during the first 3 months in high-risk diabetic patients with residual LDL-C above 70 mg/dL (with further benefit for those with residual LDL-C above ≥100 mg/dL) despite maximal tolerated dose statin and ezetimibe, patients with recent ACS, and patients with recurrent ischemic events under optimal medical therapy, multivessel coronary disease (MVD) and/or polyvascular disease (PVD), especially symptomatic PAD diabetic patients. Concerning icosapent ethyl (EPA), this drug should be introduced in patients ≥45 years of age with clinical atherosclerotic cardiovascular disease (ASCVD) or already on high-intensity or maximally tolerated statin therapy or with fasting triglycerides 135-499 mg/dL (with or without ezetimibe). Lipid-lowering treatment should be introduced as early as possible to obtain a rapid and profound decrease of LDL-c from baseline, using high-intensity statins (atorvastatin or rosuvastatin) and ezetimibe in fixed combination before discharge. Then, the strategy should be rapidly intensified by adding a PCSK9 inhibitor if the patient does not reach LDL-c levels below 55 mg/dL. We advocate this intensive strategy, which has demonstrated a further reduction in ischemic events, without safety concerns, even for patients who reach very low LDL-cholesterol levels. This approach, comprising few therapeutic steps, aims to rapidly reach LDL-c goals, improve patient compliance, and is an efficient method to fight therapeutic inertia, which remains a major issue.

Predicting the dynamic impact behaviour of spray droplets on flat plant surfaces

The dynamic impact behaviour of water droplets on plant surfaces was investigated based on a multiphase computational fluid dynamics (CFD) model. The study was conducted using the Volume Of Fluid (VOF) approach. The static contact angle of water droplets on leaf surfaces of different plants (apple, pear, leek and cabbage) was measured and found to vary between 54.9 and 138.2°. Impact experiments were conducted by monitoring the flow and impact characteristics of water droplets on leaves in still air with a high speed camera. Droplets were generated by an agricultural flat fan spray nozzle moving across the leaf at constant speed. The nozzle produced droplets with diameters ranging from 20.6 up to 550.8 μm, and droplet velocity values near the impact between 0.03 and 13.2 m s(-1). The CFD model was capable of predicting the observed dynamic impact behaviour of droplets on the plant surfaces. The fate of the droplets after the impact process for adhesion, bouncing or splashing was accurately predicted for Weber numbers (We) in the range of 0.007 to 1096 and droplet Reynolds numbers (Re) between 5 to 8000. The process was highly dependent on the surface and droplet flow characteristics during the impact. Combinations of We, Re and Ohnesorge (Oh) numbers defined the droplet maximum spread factor, the number of secondary droplets generated as a result of the splashing process and the transition between the different impact outcomes. These criteria can then be used in field scale spray deposition and drift models to better understand agricultural spray operations.

COMPUTER SIMULATIONS OF SPRAY RETENTION BY A 3D BARLEY PLANT: EFFECT OF FORMULATION SURFACE TENSION

A spray retention model was used in this study to explore theoretically the effect of a range of mixture surface tension on the spray retention and the variability of deposits. The spray retention model was based on an algorithm that tested whether droplets from a virtual nozzle intercepted a 3D plant model. If so, the algorithm determined the contribution of the droplet to the overall retention depending on the droplet impact behaviour on the leaf; adhesion, rebound or splashing. The impact outcome probabilities, function of droplet impact energy, were measured using high-speed imaging on an excised indoor grown barley leaf (BBCH12) both for pure water (surface tension of 0.072 N/m) and a non-ionic super spreader (static surface tension of 0.021 N/m) depending on the surface orientation. The modification of spray mixture properties in the simulations was performed by gradually changing the spray the droplet impact probabilities between pure water and a solution with non-ionic surfactant exhibiting super spreading properties. The plant architecture was measured using a structured light scanner. The final retention was expressed as the volume of liquid retained by the whole plant relative to the projected leaf surface area in the main spray direction. One hundred simulations were performed at different volumes per hectare and flat-fan nozzles for each formulation surface tension. The coefficient of variation was used as indicator of variability of deposits. The model was able to discriminate between mixture surface tension. The spray retention increased as the mixture surface tension decreased. The variability of deposits also decreased as the surface tension decreased. The proposed modelling approach provides a suited tool for sensitivity analysis: nozzle kind, pressure, volume per hectare applied, spray mixture physicochemical properties, plant species, growth stage could be screened to determine the best spraying characteristics maximizing the retention. The model will be further extended with the real droplet trajectories in moving airstreams.

DROPLET SIZE DISTRIBUTION MEASUREMENTS OF ISO NOZZLES BY SHADOWGRAPHY METHOD

The droplet size distribution of agricultural sprays is a key parameter during the plant protection product applications. Therefore, measurement of the drop size distribution is an important concern for spray users as well as nozzle manufacturers. The present work assessed the capability of a shadowgraphy technique to distinguish correctly the 6 spray class boundaries defined in the ISO draft standard (ISO 25358). The measurement set-up is composed by a high speed camera synchronized with a LED backlighting. The tested spray is positioned between the camera and the light. The droplets appear on the images as shadows on a brighter background. For each acquisition, two frames are recorded within a small time laps (38 μI. The droplet diameter and velocity are retrieved by using advanced image analysis algorithm on each pair of frames. Then, the drop size distribution is obtained by gathering the data retrieved from all the images. The global results showed that the 6 drop size distributions were correctly separated highlighting the ability of the method to measure small as well as large droplets using the same set-up configuration. The spatial analysis showed that the spray scanning should be extended in the minor axis direction in order to catch the whole spray.

DRIFT POTENTIAL OF TILTED SHIELDED ROTARY ATOMISERS BASED ON WIND TUNNEL MEASUREMENTS

Crop protection is mainly achieved by applying Plant Protection Products (PPP) using hydraulic nozzles, which rely on pressure, to produce a wide droplet size distribution. Because of always increased concerns about drift reduction, a wider range of low drift nozzles, such as air induction nozzles, was adopted in order to reduce the finest part of the spray. While successful for some treatments, the efficiency of coarser sprays is dramatically reduced on small and superhydrophobic target, i.e. at early stage weed control. This may be related to the increased proportion of big bouncing and splashing droplets. On the other hand, Controlled Droplet Application (CDA), using shielded rotary atomizers, stands for an improved control of droplets diameters and trajectories compared to hydraulic nozzles. Unfortunately, these atomizers, because of their horizontal droplet release, are widely recognized to produce more drift than hydraulic nozzles. The present contribution investigates whether the setting of a rotary atomizer 60 degrees forward tilted can reduce drift to acceptable levels in comparison with vertical and 60 degrees forward tilted standard and low drift flat fan nozzles for the same flow rate. In a wind tunnel, the drift potential of a medium spray produced by a tilted shielded rotary atomizer Micromax 120 was benchmarked with that of a flat fan nozzle XR11002 fine spray and that of an anti-drift nozzle Hardi Injet 015 medium spray. Operating parameters were set to apply 0.56 l/min for every spray generator. Vertical drift profiles were measured 2.0 m downward from nozzle axis for a 2 m.s(-1) wind speed. The tilted hydraulic nozzles resulted in a significant drift increase while droplets trajectories are affected by the decrease of the droplet initial vertical speed. Droplets emitted by the shielded rotary atomizer drift due to low entrained air and turbulence. A significant reduction of the cumulative drift was achieved by the rotary atomizer in comparison with flat fan nozzle while still being higher than the anti-drift nozzle. Unfortunately, the drift potential index (DIX) revealed that the cumulative drift reduction may not results in actual drift decrease because of higher drift at higher sampling locations. As a result, the DIX of the shielded rotary atomizer was similar to the standard flat-fan nozzle while the anti-drift nozzle reduced drastically drift as intended. Therefore, the 60 degrees tilted rotary atomizer failed to reach low drift levels as expected despite the reduced span.

A low-cost, multiplexable, automated flow cytometry procedure for the characterization of microbial stress dynamics in bioreactors

Background

Microbial cell population heterogeneity is now recognized as a major source of issues in the development and optimization of bioprocesses. Even if single cell technologies are available for the study of microbial population heterogeneity, only a few of these methods are available in order to study the dynamics of segregation directly in bioreactors. In this context, specific interfaces have been developed in order to connect a flow cytometer directly to a bioreactor for automated analyses. In this work, we propose a simplified version of such an interface and demonstrate its usefulness for multiplexed experiments.

Results

A low-cost automated flow cytometer has been used in order to monitor the synthesis of a destabilized Green Fluorescent Protein (GFP) under the regulation of the fis promoter and propidium iodide (PI) uptake. The results obtained showed that the dynamics of GFP synthesis are complex and can be attributed to a complex set of biological parameters, i.e. on the one hand the release of protein into the extracellular medium and its uptake modifying the activity of the fis promoter, and on the other hand the stability of the GFP molecule itself, which can be attributed to the protease content and energy status of the cells. In this respect, multiplexed experiments have shown a correlation between heat shock and ATP content and the stability of the reporter molecule.

Conclusion

This work demonstrates that a simplified version of on-line FC can be used at the process level or in a multiplexed version to investigate the dynamics of complex physiological mechanisms. In this respect, the determination of new on-line parameters derived from automated FC is of primary importance in order to fully integrate the power of FC in dedicated feedback control loops.

Vegephy: impact of vegetable oils used as extemporaneous additives on pesticide residues and their crop protection potential

Within the framework of the VEGEPHY project set up to assess the effect of refined oils used as extemporaneous additives, both alone and in combination with oligosaccharides (guar, xanthan and carboxymethyl cellulose), on the quality of plant protection treatments for wheat, a study was conducted on the effect of combinations of additives on the level of pesticide residues in wheat plants and grain and their impact on treatment efficiency. The use of some of these additives gave efficiency results that were comparable with those obtained with additives that are currently used but are not bio-based. The use of refined oils as extemporaneous additives, both alone and combined with oligosaccharides, led to better penetration by the pesticide as well as longer persistence of its activity. The experiments were conducted with fungicides, herbicides, plant growth regulators and various types of formulation (EC, SC and WG). The results obtained were conclusive, but they did depend on the physico-chemical properties of the active substance. The risk of exceeding the maximum residue levels (MRLs) of pesticides was also evaluated. Even where the MRLs had not been not exceeded, the experiments showed that in some cases the treatment with these additives could lead to pesticide residues up to two times higher than those measured for the treatment without additives. It would be necessary, therefore, to reduce the treatment dose associated with the additive and/or have a long enough pre-harvest interval to avoid exceeding the MRLs. The use of green additives could be a useful and easy way to attain the European Union (EU) goal of reducing pesticide use by improving the retention of active substances on the plant and reducing the number of treatments.

High-speed imaging use to predict spray retention on barley leaves

Measuring spray retention by plant leaves was the aim of many experiments in plant protection researches. Different methods have been used to measure spray proportion retained on vegetative surfaces, such as chemical methods using dyes and other methods using image analysis. We conducted Laboratory studies in order to validate the effectiveness of using high-speed imaging method developed by Massinon and Lebeau (2012a) to replace chemical analysis by spectrofluorometry. Measurements were performed with a high speed camera coupled with a retro-LED lighting. Sizes and velocities of the drops were extracted by image analysis and drop impact behaviours were determined by the operator. Drops were produced with a flat-fan nozzle mounted on a movable ramp. Two surfactants (Break Thru 5240 and Li700) were sprayed to highlight the effect of the reduction of surface tension. Sprays contained a fluorescent tracer for the chemical analysis, fluorescein. Relative volume proportions were computed within of an energy scale based on the Weber number. Results of high-speed imaging were compared to those of the chemical analysis by spectrofluorometry.

Assessment of the risk of dermal exposure to pesticides during treatment with a back-pack sprayer in the presence and absence of vegetation

Assessing the dermal exposure of applicators to pesticides is still an important issue, and the measurement methods used remain open to improvement. This is particularly true when it comes to characterising the exposure of applicators using back-pack sprayers. The scenarios used for the different mathematical models continue to be riddled with approximations and uncertainties. With a view to improving these scenarios, test were performed in an open environment to measure the levels of dermal exposure on various parts of an operator's body during treatment with this type of equipment. The main parameters studied are the presence of vegetation and the height of the crop. The method uses a tracer (fluorescein salt) and collectors placed all over the body in order to determine which parts are subject to most contamination during spraying. The quantitative determinations of the tracer show that exposure, in the presence of vegetation, reaches levels of 0.02%, 0.006% and 0.04% of the total quantity applied in treatment, at heights of 0.5, 1 and 2 m respectively. In the absence of vegetation, it stands at 0.21%, 0.61% and 0.62% of the total quantity applied at heights of 0.5, 1 and 2 m. In each of these situations, the lower limbs of the body (shins and thighs) collected large proportions of fluorescein. The contamination of the upper parts of the body increases in proportion to the height of treatment. These results show that the presence of vegetation and the spraying height are important parameters to be considered and to be integrated into the models, to validly assess the exposure of operators using a backpack sprayer.

Evaluation of realtime spray drift using RTDrift Gaussian advection-diffusion model

A spray drift model was developed to deliver real time information to the pesticide applicator. The sprayer is equipped with sensors to deliver real time measurement of operational parameters as spray pressure, boom height, horizontal boom movements and geolocalization. The spray droplet size spectrum as a function of pressure was characterized using PDI measurements. Wind speed and direction were measured using a sprayer mounted 2-D ultrasonic anemometer. For each successive boom position, a diffusion-advection Gaussian tilting plume model is used to compute the spray drift deposits downwind. Drift is computed independently for each droplet classes and each nozzle based on the operating parameters. Field trials were performed on a test plot in various wind conditions. The ground drift was measured for different drift distances using fluorimetry analysis. Results show that drift deposits are mainly affected by wind speed and direction what was correctly accounted for by the model. Short distance drift deposits values were overestimated by the model while long distance drift was underestimated. It appears that this most probably origins from embarked wind speed measurements and diffusion parameter. It is concluded that a treatment of embarked wind speed and diffusion measurement should be used to minimize these errors.

Effect of the entrained air and initial droplet velocity on the release height parameter of a Gaussian spray drift model

The increased concern about environmental effect of off-target deposits of pesticides use has resulted in the development of numerous spray drift models. Statistical models based on experimental field studies are used to estimate off-target deposits for different sprayers in various environmental conditions. Random-walk and computational fluid dynamics (CFD) models have been used to predict the effect of operational parameters and were extensively validated in wind tunnel. A third group, Gaussian dispersion models have been used for several years for the environmental assessment of the pesticide spray drift, mainly for aerial application. When these models were used for the evaluation of boom sprayer spray drift, their predictions were found unreliable in the short range, were the initial release conditions of the droplets have a significant effect on the spray deposits. For longer ranges, the results were found consistent with the field measurements as the characteristics of the source have a reduced influence on the small droplets drift. Three major parameters must be taken into account in order to define realistic initial conditions of the droplets in a spray drift model: the spray pattern of the nozzle, the boom movements and the effect of entrained air and droplet velocities. To take theses parameters into account in a Gaussian model, the nozzle droplet size distribution measured with a PIV setup to divide the nozzle output into several size classes. The spray deposits of each diameter class was computed for each successive position of the nozzle combining the nozzle spray distribution with drift computed with a Gaussian tilting plume model. The summation of these footprints resulted in the global drift of the nozzle. For increasing droplet size, the release height used in the Gaussian model was decreased from nozzle height to ground level using an experimental law to take into account the effect of entrained air and droplet initial velocity. The experimental law was adjusted on 2 m/s wind tunnel measurements and robustness was evaluated for 1 and 4 m/s.

Effect of tank mixed adjuvants on the drift potential of phenmedipham formulations

The aim of this paper is to analyse the effect of adjuvants and formulations on drift. The spray liquids consisted of four adjuvants (Actirob 0.4 %, Tensiofix 0.2%, Breakthru 0.2%, Silwet L-77 0.1%) with water and with two formulations of Phenmediphame (C16H16N2O4, 4.45%): an emulsion-forming (EC) and a suspension concentrate (SC). A standard flat fan nozzle at a pressure of 3 bar was used. The droplet size spectrum of each combination was determined using a Malvern granulometer. The droplet size was characterized by the volume median diameter (VMD) and the percentage of spray volume contained in droplets <100 microm (%<100). The relative drift potential was measured for each combination of formulation and adjuvant in a wind-tunnel. This latter has a working section 2.0 m wide by 2.0 m high by 6.0 m long. The air-stream is drawn by a 1.2 m diameter axial flow fan, powered by a 22 kW electric motor. Wind speed was 5 m/s. Its uniformity was controlled by a three-dimensional sonic anemometer able to move on a linear translation beam placed in the tunnel cross section. The wind-tunnel was operated under ambient conditions and three repetitions were performed randomized in order to eliminate variations in temperature and humidity for each combination. The ground spray deposits were measured on glass fibber collectors using a fluorescent tracer dye (sodium fluorescein), at a concentration of 2.5 mg/l. The statistical analysis of the droplet spectrum showed that the Phenmediphame SC formulation generated droplets of higher size than the EC. The mean VMD values were respectively equal to 228+/-11 microm and 185+/-11 microm for these formulations. For SC formulation, Break-thru decreased the VMD while Tensiofix increased the %<100. This confirmed that the degree to which an adjuvant influences spray characteristics is very variable. The drift profiles produced by the different combinations were similar, but the relative drift potential was significantly different comparing SC and EC formulations: it respectively reached 0.8+/-0,08% and 1.2+/-0,08%, whatever the adjuvant used in the liquid. Clearly, when using a flat fan nozzle to spray Phenmediphame, the droplet size and the drift potential are mainly governed by the kind of formulation, even if an interaction between the formulation and the adjuvant exists.