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Peat soils store a large part of the global soil carbon stock, which can potentially be lost when they are drained and taken into cultivation, resulting in CO2 emission and land subsidence. Groundwater level (GWL) management has been proposed to mitigate peat oxidation, but may lead to increased emissions of nitrous oxide (N2O) and methane (CH4).The aim of this experiment was to study trade-offs between greenhouse gas emissions from peat soils as a function of GWL. We incubated 1 m deep, 24 cm diameter undisturbed bare soil cores, after removal of the grass layer, from three contrasting Dutch grassland peat sites for 370 days at 16 °C. The cores were subjected to drying-wetting cycles, with the GWL varying between near the soil surface to 160 cm below the surface. We measured gas fluxes of CO2, N2O and CH4 from the soil surface, extracted pore water for DOC and mineral nitrogen analysis, and measured soil hydraulic and shrinkage characteristics.Emissions of CO2 increased after lowering the GWL, but showed different GWL-response curves during rewetting of the soil. On average, highest CO2 emissions of 1.5 g C·m−2 day−1 were found at a GWL of 80 cm below the surface. However, the 0 cm GWL was the only treatment with significantly lower CO2 emissions than other GWLs. Cumulative CO2 emissions differed significantly between sampling sites. Emissions of N2O showed a different response, peaking at GWL heights above −20 cm, particularly after a recent GWL rise. Though not significantly different, the highest N2O emissions were measured at the 0 cm GWL treatment. We confirmed this pattern for N2O in un-replicated soil cores with grass sward, although emission values were lower in these cores due to the root uptake of mineral nitrogen. CH4 emissions or −uptake remained low under any GWL. We conclude that raising the GWL is a successful strategy to reduce CO2 emissions from peat oxidation. However, raising the GWL close to the soil surface could lead to N2O emissions that negate any gains in terms of global warming potential. Our results suggest that raising the GWL in peat grasslands to −20 cm creates such a risk. A constant GWL at the surface (0 cm) would be preferential for mitigating both CO2 and N2O emissions, although such conditions don’t allow for agricultural grass production (mowing or grazing).

To reduce climate impact, switching to carbon-free electrofuels is an interesting option to reduce greenhouse gas emissions from electricity generation. The emission of other pollutants than CO2, such as nitrogen oxides (NOx), however, remains a concern. This research focuses on investigating the impact of transient phases, such as start-up and load change, on the NOx emissions expected from the rich combustion of mixtures of hydrogen and ammonia in gas turbines. Stochastic processes account for the inherent variability and uncertainty on the transient trajectories. The trajectories are simulated using a one-dimensional premixed flame model built in Cantera to compute the levels of pollutant formations, among others. The results indicate significant variations in the equivalence ratio, leading to high NOx emission peaks. The study concludes that the impact of the uncertainties related to the transient trajectories on the NOx emissions is low compared to the overall variations of the equivalence ratio, although they can accentuate observed peaks.

Residential building heating stands as a significant energy consumer with substantial environmental implications. To facilitate a sustainable transition, it is essential to assess the emissions and costs associated with current heating practices. This study investigates the economical and environmental aspects of residential building heating in the Brussels-Capital Region (BCR), Belgium. Employing a bottom-up methodology that integrates Energy Performance of Buildings (EPB) certificates with specific emissions and cost data, the analysis evaluates the emissions (including direct and indirect greenhouse gases (GHG), NOx, SO2 and PM2.5) and the levelized cost of heat (LCOH) of the existing array of heating appliances in the BCR. The analysis reveals notable variations in emissions intensity and LCOH across diverse heating technologies, highlighting the intricate interplay between environmental sustainability and economic viability. Wood and electric-powered appliances demonstrate relatively low GHG emissions compared to fossil fuel appliances. Nonetheless, individual wood-fueled appliances exhibit elevated NOx and PM2.5 emissions compared to the current weighted average emissions intensity of the BCR. Furthermore, sensitivity analysis underscores the substantial influence of fuel price scenario on the most cost-effective heating technology. This study provides a balanced framework for informed decision-making on residential building heating, offering benchmarks for transitioning to a more sustainable urban heating infrastructure.

Computational Fluid Dynamics has become a very powerful tool for developing engineering combustion devices, such as burners and furnaces. However, there are a wide variety of turbulence models, and some of them have proven to be more effective for some turbulent flow configurations than others. A reacting turbulent jet is a common flow configuration found in combustion engineering devices like burners. The present work assesses Reynolds-Average Navier-Stokes turbulence models, being tested on a CH4/H2/N2-Air reacting jet. Eight two-equation eddy-viscosity and three five-equation turbulence models were tested in the studied turbulent flow. Computational results were compared against experimental measurements in terms of flow field variables, mean mixture fraction, temperature, and species mass fraction. The findings suggest a strong influence of the turbulence model perforce on the mean mixture fraction as well as on the turbulence-chemistry interaction model. The modified version of the standard k-ε model proves to be the more reliable choice for this reactive flow configurations. Specially, where the flow patterns of the jet dictate the general flow physics. Near the fuel nozzle, both the Reynolds stress model with stress baseline k-ω (RSM-SBSL) and the standard k-ω model exhibit better agreement with experimental data than the conventional modified k-ε model. Moreover, findings from the standard modified k-ε model indicate a significant underestimation of spreading rates for radial samples in regions where jet spreading intensifies.

This study focuses on the reduced-order modeling and the operational optimization of the heating network of Université Libre de Bruxelles (ULB) to decrease its energy consumption and CO2 emissions. A reduced-order model of the network was developed, and alternatives to the current operation were investigated to minimize its operational cost. As a very first improvement, replacing the current fixed-speed pumps with optimally operated variable-speed pumps, the pumping energy can be reduced by up to 96 %. Further optimizing the network operating temperatures can lead to a reduction of the pumping energy, the heat losses and the CO2 emissions by 99 %, 19 %, and 7 %, respectively, compared to the current operation.

This paper focuses on the experimental characterization of horizontal, spiral heat exchangers used for heat recovery from sewage pipes. Such non-intrusive heat exchanger configurations are appealing for this application, but they often exhibit reduced heat exchange performances compared to more compact designs. To compare the performance of this configuration with that of an ideal counter-flow heat exchanger, a representative test setup was constructed. As the sewer pipes are generally not completely filled, tests were conducted using three different fillings (100%, 50%, 33%) and a filling parameter z was introduced in the heat transfer equations. Correction factors to be applied in the Logarithmic Mean Temperature Difference (LMTD) design method for this specific spiral configuration were derived from the test results. It was found that the filling of the sewer pipe has minimal impact on the correction factor, which ranges between 0.78 and 0.83. The average value of 0.81 is recommended for design purposes.

Objectives: This study presents 2016–2018 in vitro antimicrobial activity data and rates of resistant phenotypes for clinical isolates of Acinetobacter baumannii from Africa/Middle East, Asia/South Pacific, Europe, Latin America, and North America. Methods: A total of 4320 A. baumannii isolates were collected across all regions between 2016 and 2018. The in vitro antimicrobial activities of amikacin, colistin, levofloxacin, meropenem, and tigecycline were determined using the broth microdilution methodology of the Clinical and Laboratory Standards Institute. MICs were interpreted using the European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints (version 11.0). Rates of subsets that were resistant to amikacin, colistin, levofloxacin, and meropenem, according to EUCAST breakpoints, are also presented. Results: In each region, tigecycline and colistin were active against isolates of A. baumannii (MIC90 values, 1 or 2 mg/L) and the lowest rate of resistance was to colistin (1.2%–7.3%). The rates of resistance to the panel of agents were generally lower among A. baumannii from North America (1.3%–42.7%), compared with the other regions. Fewer than 11% of meropenem-resistant A. baumannii were also resistant to colistin. The rates of amikacin-, levofloxacin- and meropenem-resistant A. baumannii were lowest in North America and mostly higher in Africa/Middle East and Latin America. Conclusion: In each geographical region, tigecycline and colistin maintained good in vitro antimicrobial activity against isolates of A. baumannii, including antimicrobial-resistant subsets. The higher rates of meropenem-resistant isolates, particularly in Africa/Middle East and Latin America, require continued monitoring because of the scarcity of effective treatment options.

This work compares the economic viability of active and passive condensation in a medium-scale biomass combustion plant considering the variability of the return temperature and heat demand over the year. A typical District Heating plant with a total installed power of 9.5 MWth is considered. The economic feasibility is evaluated by means of the Net Present Value (NPV), Discounted Payback Period (DPP), and the Modified Internal Rate of Return (MIRR). Compared to passive condensation, the NPV of an active condensation plant is 66% higher and reduces the primary energy consumption by more than 50%. However, a higher initial investment and a higher DPP are calculated. Assuming constant return temperature and average heat demand over the year lead to an overestimation of the NPV by more than 110% for an active condensation plant and by more than 160% for a passive condensation plant. The NPV, DPP and MIRR are strongly impacted by a variation of the return temperature of the network.

Hemp-based materials have been recently proposed as adsorbents for metals present in aqueous solutions using adsorption-oriented processes. This study aims to reveal the adsorption mechanism of materials prepared from hemp shives as co-products of the hemp industry, namely sodium carbonate-activated (SHI-C) and polycarboxylic agent-grafted (SHI-BTCA) hemp shives. The interactions between copper and two hemp-based materials were characterized by different microscopic and spectroscopic techniques such as energy-disperse X-ray (EDX) spectroscopy, computed nano-tomography (nano-CT), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, and X-ray absorption near-edge structure (XANES) spectroscopy. The results showed remarkable different mechanisms for copper adsorption onto the SHI-C and SHI-BTCA hemp shives. Namely, copper surface adsorption and diffusion in the structure of the SHI-C material were predominant, whereas the adsorption of copper onto SHI-BTCA was due to a chemisorption phenomenon and ion-exchange involving the adsorbent carboxylate groups. The combination of the abovementioned complementary microscopic and spectroscopic techniques allowed us to characterize and distinguish the type of interactions involved in the liquid-solid adsorption phenomena.

Eschscholtzia californica Cham. and Valeriana officinalis L. have long been used for the management of sleep disorders and anxiety. Use of a fixed combination of these two plant extracts (Phytostandard® d’Eschscholtzia et de Valériane, PiLeJe Laboratoire, France) was investigated in an observational study. Adults with adjustment insomnia according to the criteria of the International Classification of Sleep Disorders and with an insomnia severity index (ISI) score >7 enrolled by GPs took a maximum of four tablets of the eschscholtzia and valerian combination every night for four weeks. Within one month, ISI score decreased by approximately 30% (from 16.09 ± 3.67 at inclusion (V1) to 11.32 ± 4.78 at 4 weeks (V2); p

Municipal solid waste (MSW) is increasingly considered a source of energy and materials rather than an environmental and socioeconomic problem. Incineration using the grate-firing technique is one of the best available technologies for thermal treatment of non-recyclable MSW with energy recovery. The transition to a circular economy brings a new challenge to the Waste to Energy (WtE) industry. Due to advanced waste management schemes, the calorific value of the input waste is likely to decrease. Nevertheless, WtE plant designers and operators have aimed to increase the energy and material recovery efficiency of their installations, while maintaining or even decreasing operation and maintenance costs. For these reasons, there is a need for better understanding of the chemical and physical phenomena involved in the MSW incineration process. Accurate numerical modelling of MSW packed bed combustion can substantially contribute to this objective.The literature on similar fields such as coal and biomass combustion has delineated many crucial aspects of modelling solid fuel combustion in grate-firing applications. However, the know-how obtained in these fields cannot be one on one transferred to MSW incineration because MSW is much more inhomogeneous in composition and thermophysical properties. This paper first presents an overview of MSW's chemical and thermophysical properties. Then, the heterogeneous nature of MSW and its complex thermal degradation behaviour are used as a basis to discuss the suitability of the available numerical methodologies. Finally, current challenges in the modelling of waste beds are identified, with relevance to improving the performance of industrial WtE plants.

In this paper, analytical and numerical studies of the influence of the long-range interaction parameter on the excitability threshold in a ring of FitzHugh-Nagumo (FHN) system are investigated. The long-range interaction is introduced to the network to model regulation of the Gap junctions or hemichannels activity at the connexins level, which provides links between pre-synaptic and post-synaptic neurons. Results show that the long-range coupling enhances the range of the threshold parameter. We also investigate the long-range effects on the network dynamics, which induces enlargement of the oscillatory zone before the excitable regime. When considering bidirectional coupling, the long-range interaction induces traveling patterns such as traveling waves, while when considering unidirectional coupling, the long-range interaction induces multi-chimera states. We also studied the difference between the dynamics of coupled oscillators and coupled excitable neurons. We found that, for the coupled system, the oscillation period decreases with the increasing of the coupling parameter. For the same values of the coupling parameter, the oscillation period of the Oscillatory dynamics is greater than the oscillation period of the excitable dynamics. The analytical approximation shows good agreement with the numerical results.

Changes in ocean water temperature associated with global climate change are bound to enormously affect fish populations, with potential major economic consequences in the aquaculture and fisheries industries. A link between temperature fluctuations and changes in fish stress response is well established. In this study, we aimed to assess the effects of a short- (4 days) or a long-term (4 months) exposure to warm temperature in the stress physiology of European sea bass (Dicentrarchus labrax) larvae and juveniles. First, cortisol (i.e. the main stress hormone in fishes) analysis was used to confirm that a steady and short-term elevation of temperature acts as a physiological stressful event in these fish, and cortisol release is indeed above a metabolic increase linked to temperature. Moreover, our results verified that measurement of cortisol released into the water can be reliably employed as a non-invasive indicator of acute thermal stress in experimental conditions. Secondly, the different effects on the genetic cascade underlying the stress response between long-term low or high thermal treatments were evaluated at two larval development stages via candidate-gene and whole-transcriptome approaches. Interestingly, opposite expression for some key stress genes (nr3c1, nr3c2 and hsd11b2) were observed between developmental stages, highlighting the distinct adaptive mechanisms controlling the primary and secondary responses to a stressor. Surprising expression patterns for some understudied genes involved in the stress axis were also revealed, including crhr1, mc2r, mc5r, trh or trhr, which should be further explored. Finally, evaluation of cortisol content in scales was successfully used as a biomarker of chronic thermal stress, with 10x more cortisol in fish kept at 21 °C vs 16 °C after 4 months, supporting the gene expression results observed. The use of such a method as a proxy of long-term stress, unprecedented in the literature, holds a vast array of applications in further research, in particular, in the investigation of the impact of global warming on wild fish populations.

As they deliver dispatchable renewable energy, biomass power plants are expected to play a key role in the stability of the future electricity grids dominated by intermittent renewables. Large-scale, biomass-fired power plants are often retrofitted from coal-fired plants. Such a fuel modification combined with decreasing pollutant emission limits and higher requirements in terms of load flexibility can lead to a decrease of the maximum power delivered by the unit. The limiting factors are partly related to the control systems of those plants. In this paper, we present the results of the upgrading of an 80 MWe, retrofitted biomass power plant that was achieved by improving the dynamic control of the combustion process. Thanks to the addition of virtual air flow sensors in the control system and the re-design of the combustion control loops, the undesired effects of a recent 10% power increase on NOx emissions were more than compensated. The accurate control of the local NOx production in the furnace resulted in a decrease of these emissions by 15% with an increased stability. This study will help increasing the cost-effectiveness of such conversions, and facilitate the development of dispatchable, renewable power units able to contribute to the grid stability.

The Furnace Exit Gas Temperature (FEGT) is a key parameter of the combustion process in utility boilers that needs to be accurately monitored, especially in order to increase their load- and fuel-flexibility. However, neither the average FEGT nor its spatial distribution over the boiler cross section can be measured using standard equipment. Advanced pyrometry provides an accurate and efficient way to monitor the FEGT: by combining the signals from several pyrometers installed around the boiler, the FEGT 2D field can be reconstructed. In this paper, we show the results of a measurement campaign carried out on a 1500 MWth boiler using a system comprising 9 infrared pyrometers. Thanks to online adjustments of the combustion air distribution, the FEGT peak initially observed has been reduced by approximately 100oC, and the flame has been recentered.

In this paper, we consider an array of FitzHugh-Nagumo (FHN) systems with R close neighbors. Each element (j) connects to another (m) and its 2R neighbors. Shifting these neighbors produces particular phenomena such as chimera and multi-chimera. Step traveling chimera is observed for a time dependent shift. Results show that, basing oneself on both shift parameter m and close neighbors R, a full control on the chimera dynamics of the network can be ensured.

We derive new fermionic expressions for the characters of the Virasoro minimal models M(k,2k±1) by analysing the recently introduced half-lattice paths. These fermionic expressions display a quasiparticle formulation characteristic of the ϕ2,1 and ϕ1,5 integrable perturbations. We find that they arise by imposing a simple restriction on the RSOS quasiparticle states of the unitary models M(p,p+1). In fact, four fermionic expressions are obtained for each generating function of half-lattice paths of finite length L, and these lead to four distinct expressions for most characters χr,sk,2k±1. These are direct analogues of Melzer's expressions for M(p,p+1), and their proof entails revisiting, reworking and refining a proof of Melzer's identities which used combinatorial transforms on lattice paths. We also derive a bosonic version of the generating functions of length L half-lattice paths, this expression being notable in that it involves q-trinomial coefficients. Taking the L→∞ limit shows that the generating functions for infinite length half-lattice paths are indeed the Virasoro characters χr,sk,2k±1.

In the context of global change, there is an urgent need for researchers in conservation physiology to understand the physiological mechanisms leading to the acquisition of stress acclimation phenotypes. Intertidal organisms continuously cope with drastic changes in their environmental conditions, making them outstanding models for the study of physiological acclimation. As the implementation of such processes usually comes at a high bioenergetic cost, a mitochondrial/oxidative stress approach emerges as the most relevant approach when seeking to analyze whole-animal responses. Here we use the intertidal flatworm Macrostomum lignano to analyze the bioenergetics of salinity acclimation and its consequences in terms of reactive oxygen/nitrogen species formation and physiological response to counteract redox imbalance. Measures of water fluxes and body volume suggest that M. lignano is a hyper-/iso-regulator. Higher salinities were revealed to be the most energetically expensive conditions, with an increase in mitochondrial density accompanied by increased respiration rates. Such modifications came at the price of enhanced superoxide anion production, likely associated with a high caspase 3 upregulation. These animals nevertheless managed to live at high levels of environmental salinity through the upregulation of several mitochondrial antioxidant enzymes such as superoxide dismutase. Contrarily, animals at low salinities decreased their respiration rates, reduced their activity and increased nitric oxide formation, suggesting a certain degree of metabolic arrest. A contradictory increase in dichlorofluorescein fluorescence and an upregulation of gluthathione-S-transferase pi 1 (GSTP1) expression were observed in these individuals. If animals at low salinity are indeed facing metabolic depression, the return to seawater may result in an oxidative burst. We hypothesize that this increase in GSTP1 could be a “preparation for oxidative stress”, i.e. a mechanism to counteract the production of free radicals upon returning to seawater. The results of the present study shed new light on how tolerant organisms carry out subcellular adaptations to withstand environmental change.

A test emission chamber called CLIMPAQ has been coupled to a chromatography analyzer GC to measure volatile organic compounds (VOC) concentration during a sorption experiments (Fast sorption measurements of VOCs on building materials: Part 2 – Comparison between FLEC and CLIMPAQ methods, (Rizk et al., In press) [1]). The equations used to calculate the mass transfer coefficient and the thickness of the boundary layer developed on the surface of a material are presented. In addition, the experimental profiles obtained using the CLIMPAQ chamber is also presented in the presence and the absence of a building material. Finally, the impact of chamber size on the obtained concentration profile using different chambers is shown using 3 types of chambers having different volumes, 1 m3, 30 m3 and a micro chamber of 40 mL.

Clear cell renal cell carcinoma (ccRCC) is a common human malignancy. Despite numerous efforts, there is still no reliable biomarker or combination of biomarkers available for daily practice. Our study was designed to explore the expression profile of messenger RNA (mRNA) and long non-coding RNA (lncRNA) transcripts in ccRCC in order to identify potential diagnostic biomarkers for patients with ccRCC. Total RNA from corresponding normal and malignant tissue of 15 patients with ccRCC was isolated. Expression profiling was performed using a custom Agilent gene expression microarray which allowed the analysis of 34,144 mRNA and 32,183 lncRNA transcripts. We observed that a subset of mRNA (n = 1064; 3.1%) and lncRNA (n = 1308; 4.1%) transcripts are dysregulated (fold change > 2) in ccRCC tissue. The relative higher number of differentially expressed lncRNAs indicates that lncRNA profiling may be better suited for diagnostic purposes; a number of so far unknown RNAs with potential diagnostic interest in ccRCC are identified by our gene expression profiling study. The data are deposited in the Gene Expression Omnibus (GSE61763).

In recent years, organic electrochemical transistors (OECTs) have emerged as a promising tool to add to current analytical methods due to their high-amplification capacities, robust analytical performance, and versatility. The present work proposes a compact multi-analyte transistor array with outstanding analytical performance. The ion-selective organic electrochemical transistors (IS-OECTs) were developed by combining the thick-film technology with the optimum ion-selective membrane, resulting in highly sensitive and selective IS-OECTs. The system has then been simplified using only a power supply for each OECT and a single gate electrode. To prove these advantages, the IS-OECT array of sensors has been combined with multivariate models to simultaneously detect and quantify sodium, potassium and ammonium ions in human saliva. The results obtained have been validated against reference techniques, showing promising results and confirming the usefulness of the newly developed sensing array., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Systematic errors in the calix [4] pyrrole-based potentiometric detection of creatinine have been observed in heavy smokers. This work further characterizes the interactions between the nicotinium cation and the cavitand as well as the resulting interference produced during the potentiometric detection. It is found that the nicotinium cation binds the electronic rich aromatic cavity defined by the pyrrole rings of the receptor's cone conformation with an estimated binding constant higher than 10 -4  M -1 in methylene chloride. On the other hand, the creatininium cation is preferentially included in the hydrophobic aromatic cavity of the ionophore by establishing hydrogen bond interactions with the pyrrole NHs groups. Potentiometric calibrations confirmed the detection of the nicotinium cation at neutral and acidic pH, respectively. Due to the lower pka of creatinine, a methodology to quantify creatinine in presence of nicotine by using an array of three sensors at two pH values is proposed. A partial least squares regression was performed and reported recoveries of 103% with a standard deviation of 20%. The improved determination of creatinine was therefore discussed. This approach represents a step forward in the development of effective approaches to improve the measurement of creatinine in decentralized settings., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

The use of a Pt electrode coated with a layer of Nafion has been described in previous works as an attractive way to perform the potentiometric detection of hydrogen peroxide. Despite of the attractive features of this approach, the nature of the non-Nernstian response of this system was not properly addressed. In this work, using a mixed potential model, the open circuit potential of the Pt electrode is shown to be under kinetic control of the oxygen reduction reaction (ORR). It is proposed that hydrogen peroxide acts as an oxygenated species that blocks free sites on the Pt surface, interfering with the ORR. Therefore, the effect of the polyelectrolyte coating can be understood in terms of the modulation of the factors that affects the kinetics of the ORR, such as an increase of the H + concentration, minimization of the effect of the spectator species, etc. Because of the complexity and the lack of models that accurately describe systems with practical applications, this work is not intended to provide a mechanistic but rather a phenomenological view on problem. A general framework to understand the factors that affect the potentiometric response is provided. Experimental evidence showing that the use of polyelectrolyte coatings are a powerful way to control the mixed potential open new ways for the development of robust and simple potentiometric sensors., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The development of a solid-contact potentiometric sensor based on conducting rubbers using a carbon nanotubes ink is described here. Commercial rubbers are turned into conductive ones by a simple and versatile method, i.e. painting an aqueous dispersion of single-walled carbon nanotubes on the polymer surface. On this substrate, both the working ion-selective electrode and the reference electrode are built in order to form an integrated potentiometric cell. As a proof-of-principle, selective potassium electrodes are fully characterized giving comparable performances to conventional electrodes (sensitivity, selectivity, stability, linear range, limit of detection and reproducibility). As an application of the rubber-based electrodes, a bracelet was constructed to measure potassium levels in artificial sweat. Since rubbers are ubiquitous in our quotidian life, this approach offers great promise for the generation of chemical information through daily objects., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Objective: To study the long-term outcome of Caucasian eyes with iridotrabecular trabecular apposition or peripheral anterior synechiae (PAS) and fellow eyes with narrow angles only, in eyes with intraocular pressure (IOP) <22 mm Hg at diagnosis and treated with laser peripheral iridotomy (LPI)., Design: Cohort study., Participants: Two hundred and fifty-seven Caucasian phakic patients (469 eyes) with a minimum follow-up of 2 years that had both an undilated and dilated gonioscopy after LPI., Methods: In this retrospective cohort study, we included phakic patients with a minimum follow-up of 2 years that had both an undilated and dilated gonioscopy after LPI. Excluded were patients with pseudoexfoliation, intraocular surgery, prior acute angle-closure glaucoma or antiglaucoma medication, suspicious glaucoma disk, secondary angle closure, or iridoplasty. We censored patients after any kind of intraocular surgery. Main outcome measures where the date of IOP elevation and beginning of antiglaucoma medication., Results: Four hundred and sixty-nine eyes were included. Mean follow-up was 8.5 ± 5.53 years. No apposition/PAS was observed in 84.0% of the eyes after LPI. At 10 years, 38.7% of the eyes had increased IOP and 17.3% required medication. No difference in outcomes was observed between argon and neodymium-YAG LPI or between the eyes with and without apposition/PAS before LPI. Younger patients and those with no apposition/PAS after LPI had a better prognosis (p < 0.01)., Conclusions: Many angle closure glaucoma suspects developed increased IOP and required medical treatment after LPI., (Copyright © 2011 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.)

Background: A 2-hour information session to improve understanding and compliance was offered to glaucoma patients. Three studies are presented regarding the participants, their satisfaction with the presentation, and their retention of information., Methods: One hundred consecutive patients were invited to participate. Age, sex, race, travelling distance, type of glaucoma, number of medications, duration of glaucoma, laser trabeculoplasty, trabeculectomy, medical conditions, visual acuity, visual field mean deviation, and pattern standard deviation (PSD) were documented. At the conclusion of the session, patient satisfaction was determined using a questionnaire. Responses to 6 glaucoma-related questions were requested prior to the session and again at 1, 4, and 10 months afterwards. The effects of age, sex, duration of glaucoma, drops applied, and compliance were analysed., Results: The invitation was accepted by 65.2% of all subjects, including 93.4% of those who had been undergoing therapy for less than 1 year. Factors identified in nonparticipation were advanced age, a longer duration of glaucoma, coronary heart disease, and worse PSD in the worse eye. Transportation was the main reason for nonparticipation. Patient satisfaction was excellent, and 99% indicated that they would recommend the clinic to friends with glaucoma. Patient knowledge increased and persisted throughout the 10 months. Older participants had lower scores., Interpretation: Most patients wanted to participate in the information session. Participants subjectively felt that the session was useful. It improved their knowledge of glaucoma, and has the potential to increase patient compliance.

Background: Allergic reactions to ophthalmic drugs have not been studied extensively in ophthalmology. We performed a study to estimate the incidence of allergy to brimonidine in patients treated for glaucoma., Methods: We identified all patients in a private glaucoma practice who started therapy with brimonidine between Mar. 19, 1998, and Aug. 14, 1999. We recorded the patient's diagnosis, age, sex, concomitant glaucoma medication, previous allergy to glaucoma medication and allergy to brimonidine. Allergy was defined as allergic contact dermatoconjunctivitis or follicular conjunctivitis., Results: Of the 140 patients identified, 36 (25.7%) had had an allergic reaction to brimonidine. Contact dermatoconjunctivitis was noted in 19 patients (52.8%) and follicular conjunctivitis in 18 (50.0%). The rate of development of those two manifestations was linear and almost parallel throughout the study period. In logistic regression analysis previous allergy to a topically given antiglaucoma medication (t = -5.13) and concurrent use of levobunolol (t = 3.46) were retained as the most probable predictor variables of allergy to brimonidine. Life-table analysis showed a fairly linear curve, with no peak in allergy rate. Allergic reactions occurred throughout the year, with a small peak in March., Interpretation: We found a rate of allergy to brimonidine of 25.7%. Concomitant levobunolol use and allergy to another glaucoma medication were associated with a higher allergy rate.

This update, intended for cardiologists, is not concerned with technical surgical considerations but rather considers the problems facing the physician in abdominal aortic aneurysm (AAA). 1) What form does AAA take: an atheromatous, spindle-shaped and partially thrombotic ectasis. 2) How is it detected: traditionally by clinical examination and increasingly by ultrasound. 3) What additional examinations are useful: the most simple and commonly repeated is ultrasound. Aortic angiography is useful only in cases with a surgical indication. 4) What is the risk of spontaneous development: above all, rupture, the statistical risk of which becomes considerable once the diameter of the aneurysm exceeds 6 cm. 5) What are the risks and results of surgical treatment: it has become an operation presenting little danger and one that beyond all doubt increases life expectancy. 6) Which patients should undergo surgery: all aneurysms dating from more than 6 cm and/or showing symptoms.

Aortic valve insufficiency with ventricular septal defect is usually treated by plication of the commissures. However, long-term deterioration is common. We propose a new technique that corrects the aortic annulus dilatation and the leaflet prolapse and reinforces the sinus of Valsalva. Two groups were compared: group I (29 patients) had plication of the prolapsed leaflet(s) and folding of the free edge; group II (26 patients) had triangular resection of the prolapse cusp, annuloplasty, and reinforcement of the aortic wall. The two groups were similar with regarding to preoperative clinical data. There was no perioperative mortality. Primary failure (aortic valve replacement) occurred in 8 patients in group I (28%) and in 2 patients in group II (8%). The rate of secondary failure was 31% in group I and 4% in group II. The actuarial rate of freedom from reoperation at 5 years is 55% in group I and 88% in group II (p less than 0.05). The late mortality was 6.5% in group I and 10.9% in group II (no difference). We conclude that aortic valve insufficiency with ventricular septal defect is a malformation of the aortic leaflets, the annulus, and the sinus of Valsalva, and that the proposed technique offers a better result than the usual methods in terms of residual aortic valve insufficiency.

The sympathetic system is composed of alpha and beta receptors. Beta blockers block the beta effect competitively. They slow the heart and decrease its contractile strength. They block bronchodilatation and the vasodillation of muscular arteries. Timolol is a non specific beta blocker. It decreases intraocular pressure by reducing aqueous humor formation. It does not change outflow facility. Its action starts twenty minutes after a topical drop, is maximum two to four hours later and lasts 24 hours and more. Timolol o.50% seems equivalent to pilocarpine 4% while Timolol 0.25% seems equivalent to epinephrine 2%. There is a further drop in pressure when added to pilocarpine, diamox as maximum medical treatment. Tables show its advantages, drawback, adverse reactions, and precautions to be taken.

Prolapsed leaflet is the result of ruptured chordae, elongated chordae, or ruptured papillary muscle. Various techniques adapted to each of these lesions were developed, and repair of 213 prolapsed mitral valves was performed between 1969 and 1977. There were 109 patients with ruptured chordae treated by quadrangular resection of the prolapsed leaflet; 103 patients with elongated chordae were treated by either a "sliding plasty" of the papillary muscle or a "shortening plasty" of the chordae; and 1 patient with ruptured papillary muscle was treated by reimplantation. The great majority of patients had an associated annular dilatation or deformation requiring the use of a Carpentier ring to remodel the annulus and reinforce the repair. The operative mortality was 4% and the late mortality, 3%. There were 6 reoperations, 3 of which occurred within 1 year. Thromboembolic complications occurred in only 1 patient (0.5%), even though the majority of patients received no anticoagulation treatment. Actuarial curves demonstrated a 91% survival at 8 years.

In a double-blind controlled study seven healthy subjects with normal eyes were given alternatively a placebo or 80 or 160 mg of propranolol per day, with an interval of at least 1 week between the three experiments. Two hours after a dose of the medication was taken, two drops of 0.5% timolol maleate were instilled into one eye, and for the next 4 hours the intraocular pressure, pulse rate and blood pressure were measured hourly. Timolol reduced the intraocular pressure substantially and to the same extent in the subjects who had taken a placebo and those who had taken 80 mg of propranolol per day; however, it had almost no effect in those who had taken 160 mg of propranolol per day. There was marked interindividual variation in the response to timolol. No change in the pulse rate or the blood pressure was noted. A similar study was carried out with 12 patients taking propranolol for various cardiovascular problems; their dosage of this agent was not varied, however. The results were basically the same, except that the patients taking 120 mg of propranolol per day had an intermediate response to timolol.

In this retrospective study the results of trabeculectomy in 21 patients with open-angle glaucoma and no previous eye surgery who were followed up for at least 1 year were analysed. In 10 patients sodium hyaluronate had been injected during the operation to cushion the anterior chamber; the other 11 patients served as controls. The two groups had been comparable preoperatively with respect to characteristics assessed postoperatively. The subjects in the sodium hyaluronate group had better visual acuity and less postoperative hypotony. Although the series was too small to statistically validate the following observations, these subjects had better visual fields, their intraocular pressure was easier to control, and they had fewer complications; in particular, none had collapse of the anterior chamber.

Timolol and epinephrine may have cardiovascular effects when used alone topically. These drugs are partial pharmacologic antagonists at the adrenergic beta-receptor. When a placebo, 2% epinephrine hydrochloride or 0.1% dipivefrin hydrochloride was instilled in a randomized, double-blind fashion in eyes treated with timolol maleate no change in heart rate, intraocular pressure or rate of aqueous outflow was noted. The systolic blood pressure did not increase, but with epinephrine a slight increase in diastolic blood pressure was noted. Moreover, cardiac arrhythmias appeared after the use of epinephrine. The pupil enlarged after the instillation of epinephrine or dipivefrin.

Between January 1982 and December 1983 stereo colour photography covering 10 standard fields of 30 degrees and fluorescein angiography were performed in 64 consecutive patients with diabetes mellitus who had no clinical evidence of diabetic retinopathy. Fifty-two patients were excluded on the basis of the slightest photographic or angiographic evidence of retinopathy or any other ocular disease. Electroretinogram oscillatory potentials were recorded in the remaining 12 patients. Four of the 12 had normal oscillatory potentials, colour photographs and angiograms, while 8 had angiographic evidence of lobular delayed choroidal perfusion and abnormal oscillatory potentials. Although only a small number of patients in the preclinical stages of diabetic retinopathy were studied, the results warrant that further attention be given to lobular delayed choroidal perfusion, which may represent early evidence of choroidal involvement in diabetic retinopathy.

Two hundred fifty-three patients who underwent isolated mitral valve replacement with a porcine bioprosthesis had long-term evaluation. One hundred forty-seven patients received a Carpentier-Edwards porcine bioprosthesis and 106, a Hancock valve. There were no significant differences in preoperative clinical characteristics between the two groups. Cumulative follow-up was 1,375 patient-years. At 10 years, 93% +/- 2.5% of the patients in the Carpentier-Edwards group and 85% +/- 7.8% of those in the Hancock group were free from valve-related death (not significant), and 95% +/- 2% and 91% +/- 3.8%, respectively, were free from thromboembolism (not significant). At 10 years, 65% +/- 7.2% of the patients in the Carpentier-Edwards group and 66% +/- 7.2% of those in the Hancock group were free from structural valve deterioration (not significant), and 64% +/- 6% and 59% +/- 7.3%, respectively, were free from reoperation (not significant). We conclude that the first generation of Carpentier-Edwards and Hancock prostheses produce comparable long-term results in the mitral position.

Three groups of animals were studied during the four-hour period following their recovery from total occlusion of retinal circulation for periods of 30, 60 and 90 minutes. During incremental increases of ischemia, recovery followed a pattern that is the reverse of that previously reported, inasmuch as wave amplitude is concerned. From total extinction, ERGs recovered and showed hyperresponses. Delays, however, behaved differently: they increased with recovery time--the opposite of what was expected. All signs were inversely proportional to the duration of ischemia. Sixty minutes of occlusion appears to be a threshold beyond which ERGs do not recover as well.