Mass transfer modelling of the extraction of antibiotics from aqueous solution using Biosurfactants

International audienceThe objective of this work is to modelling a new separation technique based on the removal of antibiotics such as amoxicillin and ampicillin produced by antibiotical company Saidal Médéa (Algeria) from pharmaceutical effluents using biosurfactants and commercial surfactants. The kinetic distribution of amoxicillin and ampicillin between the two phases was modelled in order to well understand the mechanism governing the direct transfer of antibiotics from the aqueous phase to the micellar phase. The results were interpreted in terms of a two-film theory for flat interface. The model of the kinetic transfer developed in this study provides excellent predictions. A very good correlation between predicted and experimental values was found : R2 = 0.98 for the sorption onto biosurfactant and R2 = 0.99 onto a synthetic surfactant. The model coefficients were used to estimate the overall combined mass transfer coefficient and the individual mass transfer coefficients

Komparativna terapeutska svojstva ekstrakta češnjaka i metformina na hiperglikemiju, hiperkolesterolemiju i hipertrigliceridimiju kod štakora s dijabetesom tipa 1 induciranim aloksanom

The current pilot study was conducted to compare the triple effect of garlic extract and metformin on hyperglycaemia, hypercholesterolaemia, and hypertriglyceridaemia in alloxan-induced type 1-like diabetic rats. Wistar rats were randomly divided into four groups. Control group included normal rats. The second group included alloxan-induced type 1-like diabetic rats, receiving no treatment. The other two groups of diabetic rats were orally treated with 0.75 g of garlic extract per kg of body weight and 0.05 of metformin g per kg of body weight respectively for four weeks. The pharmacological impact of garlic compounds on serum glucose and lipids as opposed to the glucose-lowering and lipid-lowering was highlighted in these experiments. These results revealed that garlic extract has a triple action on hyperglycaemia, hypertriglyceridemia, and hypercholesterolemia. Its effect on hyperglycaemia is long lasting, and more pronounced compared to the metformin. Interestingly, it had a regulatory effect on glycaemia as highlighted in the control group. This work is licensed under a Creative Commons Attribution 4.0 International License.Ovo pilot-istraživanje provedeno je da bi se usporedio trostruki učinak ekstrakta češnjaka i metformina na hiperglikemiju, hiperkolesterolemiju i hipertrigliceridemiju kod štakora s dijabetesom tipa 1 induciranim aloksanom. Štakori Wistar nasumično su bili podijeljeni u četiri skupine. Kontrolna skupina sadržavala je normalne štakore. Druga skupina bili su netretirani štakori s dijabetesom (dijabetes tipa 1, induciran aloksanom). Preostale dvije skupine štakora s dijabetesom liječene su četiri tjedna ekstraktom češnjaka doziranim 75 g po kilogramu tjelesne težine, odnosno metforminom u dozi 0,05 g po kilogramu tjelesne težine. Navedeni spojevi unosili su se oralnim putem. U istraživanjima naglašen je farmakološki utjecaj spojeva iz češnjaka na glukozu i lipide u serumu. Dobiveni rezultati pokazali su da ekstrakt češnjaka ima trostruko djelovanje na: hiperglikemiju, hipertrigliceridemiju i hiperkolesterolemiju. Njegov učinak na hiperglikemiju dugotrajan je i izraženiji u usporedbi s metforminom. Zanimljivo je da je djelovao regulacijski na glikemiju. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna

Comparative Therapeutic Properties of Garlic Extract and Metformin on Hyperglycaemia, Hypercholesterolaemia, and Hypertriglyceridaemia in Alloxan-induced Type1-like Diabetic Rats

The current pilot study was conducted to compare the triple effect of garlic extract and metformin on hyperglycaemia, hypercholesterolaemia, and hypertriglyceridaemia in alloxan-induced type 1-like diabetic rats. Wistar rats were randomly divided into four groups. Control group included normal rats. The second group included alloxan-induced type 1-like diabetic rats, receiving no treatment. The other two groups of diabetic rats were orally treated with 0.75 g of garlic extract per kg of body weight and 0.05 of metformin g per kg of body weight respectively for four weeks. The pharmacological impact of garlic compounds on serum glucose and lipids as opposed to the glucose-lowering and lipid-lowering was highlighted in these experiments. These results revealed that garlic extract has a triple action on hyperglycaemia, hypertriglyceridemia, and hypercholesterolemia. Its effect on hyperglycaemia is long lasting, and more pronounced compared to the metformin. Interestingly, it had a regulatory effect on glycaemia as highlighted in the control group

A Quantitative Structure Activity Relationship for acute oral toxicity of pesticides on rats: Validation, Domain of Application and Prediction

International audienceQuantitative Structure Activity Relationship (QSAR) models are expected to play an important role in the risk assessment of chemicals on humans and the environment. In this study, we developed a validated QSAR model to predict acute oral toxicity of 329 pesticides to rats because a few QSAR models have been devoted to predict the Lethal Dose 50 (LD50) of pesticides on rats. This QSAR model is based on 17 molecular descriptors, and is robust, externally predictive and characterized by a good applicability domain. The best results were obtained with a 17/9/1 Artificial Neural Network model trained with the Quasi Newton back propagation (BFGS) algorithm. The prediction accuracy for the external validation set was estimated by the Q2ext and the Root Mean Square error (RMS) which are equal to 0.948 and 0.201, respectively. 98.6% of external validation set is correctly predicted and the present model proved to be superior to models previously published. Accordingly, the model developed in this study provides excellent predictions and can be used to predict the acute oral toxicity of pesticides, particularly for those that have not been tested as well as new pesticides

Predviđanje klimatskih parametara iz fizikalno-kemijskih parametara pomoću umjetnih neuronskih mreža: studija slučaja Ain Defla (Alžir)

The knowledge of the climate of a region is a primordial task in that it allows predictions of climatic parameters in the future. In this study, monthly maximum and minimum air temperature (Tair,min, Tair,max), relative humidity (RH), and sunshine duration (SD) were modelled by multiple linear regression (MLR), and multilayer perceptron methods (MLP). For the four climatic parameters, the internal and external validations of MLP-ANN model showed high R2 and Q2 values in the range 0.81–0.98. The agreement between calculated and experimental values confirmed the ability of ANN-based equation to predict these parameters quickly and at lower cost. This work is licensed under a Creative Commons Attribution 4.0 International License.Poznavanje klime neke regije osnovni je zadatak jer omogućuje predviđanje klimatskih parametara u budućnosti. U ovom su istraživanju maksimalna i minimalna mjesečna temperatura zraka (Tair,min, Tair,max), relativna vlažnost (RH) i trajanje sunčeve svjetlosti (SD) modelirani višestrukom linearnom regresijom (MLR) i višeslojnim perceptronskim metodama (MLP). Za četiri klimatska parametra interna i eksterna validacija modela MLP-ANN pokazala je visoke vrijednosti R2 i Q2 u području 0,81 – 0,98. Usklađenost izračunatih i eksperimentalnih vrijednosti potvrdilo je da jednadžba temeljena na ANN-u brzo i uz niže troškove predviđa te parametre. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna

Preventivna aktivnost đumbira (Zingiber officinale) u suzbijanju mijelotoksičnosti i hepatotoksičnosti izazvane cikloheksatrienom i identifikacija najaktivnijih spojeva metodom GC-MS

This study aimed to uncover the preventive capability of Zingiber officinale against myelotoxicity, leukaemia, and hepatotoxicity. For the most part, this work depended on the subcutaneous injection of cyclohexatriene in rabbits to cause the illness by a synthetic strategy. In parallel, another group of rabbits was exposed to the injection of cyclohexatriene under similar conditions with the feeding Zingiber officinale, where it was discovered that the cyclohexatriene-induced myelotoxicity was counteracted. The histological examination additionally uncovered the hepato-defensive intensity of Zingiber officinale. The most pharmacologically active molecules of Zingiber officinale were recognised by gas chromatography–mass spectrometry (GC-MS).Cilj ove studije bio je otkriti preventivnu sposobnost Zingiber officinale u suzbijanju mijelotoksičnosti, leukemije i hepatotoksičnosti. Ovaj je rad većim dijelom temeljen na potkožnom ubrizgavanju cikloheksatriena u kuniće da bi se sintetskom strategijom izazvala bolest. Usporedno s time, druga skupina kunića bila je izložena injekciji cikloheksatriena u sličnim uvjetima s hranjenjem Zingiber officinale, gdje je otkriveno da je suprotstavljena mijelotoksičnost izazvana cikloheksatrienom. Histološkim pregledom dodatno je otkriven hepatoprotektivni intenzitet Zingiber officinale. Najviše farmakološki aktivnih molekula Zingiber officinale prepoznato je metodom plinske kromatografije–masene spektrometrije (GC-MS)

QSAR modeling in ecotoxicological risk assessment: application to the prediction of acute contact toxicity of pesticides on bees (Apis mellifera L.)

International audienceDespite their indisputable importance around the world, the pesticides can be dangerous for a range of species of ecological importance such as honeybees (Apis mellifera L.). Thus, a particular attention should be paid to their protection, not only for their ecological importance by contributing to the maintenance of wild plant diversity, but also for their economic value as honey producers and crop-pollinating agents. For all these reasons, the environmental protection requires the resort of risk assessment of pesticides. The goal of this work was therefore to develop a validated QSAR model to predict contact acute toxicity (LD) of 111 pesticides to bees because the QSAR models devoted to this species are very scarce. The analysis of the statistical parameters of this model and those published in the literature shows that our model is more efficient. The QSAR model was assessed according to the OECD principles for the validation of QSAR models. The calculated values for the internal and external validation statistic parameters (Q and [Formula: see text] are greater than 0.85. In addition to this validation, a mathematical equation derived from the ANN model was used to predict the LD of 20 other pesticides. A good correlation between predicted and experimental values was found (R  = 0.97 and RMSE = 0.14). As a result, this equation could be a means of predicting the toxicity of new pesticides

Modeling of transitional pore blockage to cake filtration and modified fouling index – Dynamical surface phenomena in membrane filtration

International audienceThe objective of this study was to optimize and to model the membrane fouling process. The modeling was based on two approaches, dynamical and phenomenological with the combination of surface phenomena. The established model was a transitional pore blockage model towards cake fouling through new characteristic parameters and a modified fouling index. The characteristic parameters developed in this study described the effect of cake restructuring, the shear, the mass of the cake, the filtered fluid recirculation according to the effective thickness Z c in the membrane fouling mechanism. The Modified fouling index-Dynamical surface phenomena (MFI-DSP) was developed by characteristics of multiple interactions forces ratio and mechanical forces in the transition of the regime. The membrane fouling was carried out according to the membrane compressibility factor m = 1, the cake n = [0-1] and the kinetics of the fouling process corresponding to the partial orders ω = [0-4]. The new model was validated based on experimental data in tangential and frontal filtration, using PES-10, UE-100 and NF-270 membranes with the prediction of the transitional blockage. Statistical analyzes at CI ≥ 95% showed better performance and efficiency of the new model compared to the existing models focused on the absolute relative error, the correlation coefficient, the number of characteristic parameters in the prediction, the characterization of the fouling process, as well as in the transition from pore blockage to cake filtration

Removal of Amoxicillin Antibiotic from Aqueous Solution Using an Anionic Surfactant

International audienceA novel separation technique based on an aqueous surfactant extraction to remove organic contaminants from aqueous solutions was investigated. A model was developed regarding the kinetic partitioning of amoxicillin and regarding the mechanism governing the forward transfer of amoxicillin in a reverse micelle system. Results were interpreted in terms of a two-film theory for flat interface. To confirm the relevance of the developed separation technique, it was applied to the elimination of amoxicillin by adsorption on an anionic surfactant, sodium dodecyl sulfate. The effects of various parameters such as contact time, pH, temperature, and initial concentration of sodium dodecyl sulfate were investigated at an agitation speed of 350 rpm. The percentage of maximum adsorption capacity of amoxicillin was found to be 87.7 % for the following optimal conditions: amoxicillin concentration of 4 mg/L, 40 min contact time, pH 4, 50 °C, and 0.01 g/L initial sodium dodecyl sulfate concentration. The results showed that the pseudo-first-order model provides most adequate correlation of experimental data compared to the pseudo-second-order model. Three statistical functions were used to estimate the error deviations between experimental and theoretically predicted kinetic adsorption values, including the average relative error deviation (ARED), the sum of the squares of the errors (SSE), and the standard deviation of residuals (S res). The results showed that, both Freundlich equation and pseudo-first-order equation provide the best fit to experimental data. Adsorption isotherm data appeared to be accurately described by a Freundlich model. The thermodynamic parameters (∆G, ∆H, and ∆S) showed that the process was feasible, spontaneous, and exothermi

New Alternative of Enhancing Hospital Hygiene Facing Pseudomonas aeruginosa Drug Resistance Impact of Hypertonic Saline Solutions on the Behavior of P. aeruginosa

International audienceThe objective of this study was to elucidate the antibacterial effect of hypertonic saline of KH 2 PO 4 and NaCl solutions for enhancing hospital hygiene facing drug resistance of the biofilm of Pseudomonas aeruginosa isolated from a hospital environment on an agar cetrimide medium. The variations of P. aeruginosa biofilm density were measured following optical surface density by a correlated imaging method. Inhibition tests of 90% of the biofilm in a selective liquid medium monitored by spectrophotometry showed inhibition rates of 91.2 and 91.1% for minimal biofilm inhibition concentrations of 5.4 and 3.6% for NaCl and KH 2 PO 4 , respectively. The results of the eradication tests of 50% of the biofilm showed minimal biofilm eradication concentrations of 6.3 and 3.6% and eradication ratios of 50.6 and 50.9% for NaCl and KH 2 PO 4 , respectively. In the case of a selective solid medium, the results exhibited a minimal biofilm inhibition concentration of 4.2 and 3.9%, a biofilm inhibition rate of 90.8 and 90.5%, and a minimal biofilm eradication concentration of 2.7 and 3.3% for a biofilm killing quotient of 55.0 and 61.2% in NaCl and KH 2 PO 4 cases, respectively. Accordingly, the results obtained demonstrated the potential of the hypertonic saline solutions and suggested that the employment of these solutions in hospital hygiene can be an alternative of prevention of nosocomial infections by P. aeruginosa