Dactylifera L) on the biochemical indicators of lead poisoning in male Wistar rats

This study is conducted to examine the effect of the oral administration of pectin of dates on perturbation of the biochemical parameters induced by lead. Male rats were exposed to lead acetate at 350mg/Kg for one month, after this period, rats treated during one month with the pectin of date at 3%. Rats were sacrificed, the blood and urine are collected for the biochemical assays: glucose, total protein, phosphatase acide (PAC), alkaline phosphatase (PAL), aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, urea and uric acid. The results showed that the exposure to lead has induced a disturbance in the biochemical parameters. Thus, the treatment by the pectin of dates reduced the high concentration of these parameters. Our results show that the pectins of dates may have a corrective effect on the biochemical disturbances induced by the lead.Keywords: Phoenix Dactylifera, Pectin, Lead, Biochemical parameter

Optimizing the design of timber components under decay and climate variations

International audienceThe durability of timber structures can be affected by the isolated or combined actions of loading, moisture content, temperature, biological activity, etc. This work focuses on the optimal design of new timber structures subjected to deterioration. Since the deterioration processes and the structural behavior of timber structures are complex, nowadays the deterioration models are not able to account for all influencing factors. Consequently, this study is based on an empirical model that was derived based in-lab experimental studies for the decay growth of brown rot in pine sapwood under variant climate conditions. Such a model is divided into two processes: (i) activation process and (ii) mass loss process. On the other hand, there are significant uncertainties involved in the problem. The uncertainties inherent to materials properties, models and climate are considered throughout a time-dependent reliability based-design optimization (TD-RBDO) approach. The TD-RBDO aims to ensure a target reliability level during the operational life. This approach is applied to design optimization of a new timber component subjected to different French climates. The performance of the optimized solution is compared with a traditional cross-section designed according to the Eurocode 5 in terms of safety. The overall results indicate that an optimized solution ensures a target reliability level during the whole structural lifetime

Theoretical analysis of the spatial variability in tillage forces for fatigue analysis of tillage machines

This paper presents a new theoretical model to describe the spatial variability in tillage forces for the purpose of fatigue analysis of tillage machines. The proposed model took into account both the variability in tillage system parameters (soil engineering properties, tool design parameters and operational conditions) and the cyclic effects of mechanical behavior of the soil during failure ahead of tillage tools on the spatial variability in tillage forces. The stress-based fatigue life approach was used to determine the life time of tillage machines, based on the fact that the applied stress on tillage machines is primarily within the elastic range of the material. Stress cycles with their mean values and amplitudes were determined by the rainflow algorithm. The damage friction caused by each cycle of stress was computed according to the Soderberg criterion and the total damage was calculated by the Miner's law. The proposed model was applied to determine the spatial variability in tillage forces on the shank of a chisel plough. The equivalent stress history resulted from these forces were calculated by means of a finite element model and the Von misses criterion. The histograms of mean stress and stress amplitude obtained by the rainflow algorithm showed significant dispersions. Although the equivalent stress is smaller than the yield stress of the material, the failure by fatigue will occur after a certain travel distance. The expected distance to failure was found to be df=0.825×106km. It is concluded that the spatial variability in tillage forces has significant effect on the life time of tillage machines and should be considered in the design analysis of tillage machines to predict the life time. Further investigations are required to correlate the results achieved by the proposed model with field tests and to validate the proposed assumptions to model the spatial variability in tillage force

Identification probabiliste des paramètres élastiques d'un circuit imprimé

Les systèmes mécatroniques embarqués sont soumis à des vibrations provoquant la rupture des joints brasés par fatigue. L'estimation de la durée de vie en fatigue est liée à la connaissance des propriétés dynamiques des matériaux du circuit imprimé. Dans cette communication l'identification du modèle probabiliste est effectuée à partir de mesures expérimentales réalisées par la technique de vibrométrie à balayage laser 3D. En outre, le problème inverse probabiliste vise à quantifier les incertitudes des propriétés des matériaux afin de mieux évaluer l'aléa de la réponse du modèle numériqu

Neuroprotective effect of wormwood against lead exposure

<b>Background</b> : Lead poisoning is a potential factor in brain damage, neurochemical dysfunction and severe behavioral problems. Considering this effect, our study was carried out to investigate the effects of wormwood to restore enzymes activities, lipid peroxidation and behavioral changes induced by lead. <b>Methods</b> : Thirty Wistar rats were divided into five groups (<i>n</i> = 6 in each group): three groups exposed to 750 ppm of lead acetate in the drinking water for 11 weeks and two groups as control. Aqueous wormwood extract (200 mg/kg body weight) was administrated to intoxicated (Pb(-)&#x002B;A.AB) and control groups (A.AB) for four supplemental weeks. Activities of acetylcholinesterase (AchE), monoamine oxidase (MAO) and thiobarbituric acid-reactive substances (TBARS) level were determined in the hypothalamus, hippocampus, cortex and striatum of male rats and the grooming and locomotors activity were defined in all groups. Results: The intoxicated group (Pb) has a significantly increased TBARS value compared with the control in all <b>brain</b> regions (<i>P</i> &lt; 0.05) and, after treatment with the wormwood extract, a significant reduction was noted. The enzyme activity decreased significantly (<i>P</i> &lt; 0.05) in the Pb group compared with the control, essentially for the hippocampus (AchE: -57&#x0025;, MAO: -41&#x0025;) and the striatum (AchE: -43&#x0025;, MAO: -51&#x0025;). After wormwood extract administration, the AchE and MAO activity were significantly increased in all brain regions compared with the Pb group (<i>P</i> &lt; 0.05). The behavioral test (locomotors and grooming test) indicates a significant hyperactivity in the Pb group compared with the control group. After treatment with wormwood extract, the Pb(-)&#x002B;A.Ab indicates a lower activity compared with Pb. <b>Conclusion</b> : These data suggest that wormwood extract may play a very useful role in reduction of the neurotoxicological damage induced by lead

CHEMICAL COMPOSITION OF ESSENTIAL OIL FROM Atriplex lentiformis LEAVES

International audienc

Prophylactic effects of Wormwood on lipid peroxidation in an animal model of lead intoxication

The ability of Wormwood (Artemisia absinthium L.) extract (A.Ab) to restore membrane-bound enzymes like Na+-K+-ATPase, Ca++-ATPase, Mg++-ATPase, and oxidative damage induced by lead were investigated. Rats were exposed to lead acetate (750 ppm) for 11-weeks and treated during 4-weeks with A.Ab. Lipid levels, ATPase activity, thiobarbituric acid reactive substances (TBARS), and proteins carbonyl were estimated. In liver and kidney, lead acetate inhibited membrane-bound enzymes and increased (P < 0.05) the levels of cholesterol, triglycerides, free fatty acids, phospholipids, TBARS, and carbonyl proteins. After 4 weeks, the intoxicated group who received A.Ab showed a significant reduction in TBARS and carbonyl levels in liver and kidney compared to group exposed to lead. A.Ab restored the levels of membrane-bound enzymes and lipid levels to near normal. These results indicate that aqueous Wormwood extract had a significant antioxidant activity and protect liver and kidney from the lead-induced toxicity