Akutna neurotoksičnost acetaminofena u pilića

Acetaminophen is a non-steroidal drug used as an anti-inflammatory, analgesic and antipyretic in humans and animals. In chicks, neurotoxicity associated with acetaminophen has not been fully elucidated. The aim of this study was to identify the neurobehavioral, biochemical and histopathological effects of acetaminophen in 7 day-old broiler chicks. The acute LD50 of acetaminophen was estimated by the up- and- down method, and then the influence of acetaminophen on the open field activity and tonic immobility test was recorded. The behavioral signs and toxicity scores were recorded. The liver enzymes, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities were estimated. Histopathology of the brain and liver were performed. The acetaminophen LD50 value in chicks was 1077 mg/kg, intramuscularly. Acetaminophen reduced the general locomotive activity of the chicks, measured in the open- field arena, as a result of a significant rise in latency in moving from the central square, and a reduction in the numbers of lines crossed as well as reduction in the vocalization score compared to the control. Intramuscular injections of acetaminophen at doses of 500 and 1000 mg/kg induced signs of toxicosis, such as head dropping, closed eyelids, immobility, loss of vocalization, and recumbency, followed by death. Histopathological examination of the brain showed the presence of congestion of blood vessels, vasogenic edema and necrosis of Purkinje cells. Degenerative changes and liver enzyme function showed liver dysfunction. Our results show behavioral, biochemical and histopathological data demonstrating that acetaminophen at high doses produced acute neurotoxicity in chicks.Acetaminofen je nesteroidni lijek koji se upotrebljava kao protuupalno, analgetičko i antipiretičko sredstvo u ljudi i životinja. U pilića nije potpuno poznata povezanost neurotoksičnosti i acetaminofena. Cilj ovog istraživanja bio je identificirati neurobihevioralne, biokemijske i histopatološke učinke acetaminofena u sedmodnevnih brojlera. Akutni LD50 acetaminofena procijenjen je metodom “up and down” nakon čega je zabilježen utjecaj acetaminofena na aktivnost na otvorenom i toničnu nepokretnost. Zabilježeni su bihevioralni znakovi i razina toksičnosti. Izmjerene su vrijednosti jetrenih enzima, aktivnost aspartat-aminotransferaze (AST) i alanin-aminotransferaze (ALT). Učinjena je histopatološka pretraga mozga i jetre. Vrijednost LD50 acetaminofena u pilića bila je 1077 mg/kg, intramuskularno. Acetaminofen je smanjio opću lokomotornu aktivnost i stupanj glasovnog izražavanja pilića na otvorenom prostoru, kao posljedica znakovitog porasta latencije u odnosu na piliće kontrolne skupine. Intramuskularna injekcija acetaminofena u dozama od 500 i 1000 mg/kg izazvala je znakove toksikoze kao što su padanje glave, spušteni kapci, nepokretnost, gubitak glasa, ležeći pložaj te smrt. Histopatološka pretraga mozga pokazala je kongestiju krvnih žila, vazogeni edem i nekrozu Purkinjeovih stanica. Došlo je do degenerativnih promjena i disfunkcije jetre što su pokazali jetreni enzimi. Bihevioralni, biokemijski i histopatološki podaci iz ovog istraživanja pokazali su da acetaminofen u visokim dozama uzrokuje akutnu neurotkosičnost u pilića

Heuristic Dispatching Rules for Dynamic Scheduling of Heavy Engineering Equipments

Dynamic scheduling problem has been an attractive area for researches to investigate since a long time. Many techniques have been used to tackle such problems, but all of these techniques require high efforts to formulate the dynamic scheduling problems inorder to obtain optimal solution. Using Heuristic or dispatching rules to solve the dynamic scheduling problem is efficient and popular manner to reach an acceptable level of scheduling. In this paper hybrid techniques are used in the proposed developed model. First the switching of four dispatching rules (Earliest Due Date (EDD), Slack Time (SLACK), Slack / Remaining Operations (S/ROP) and Priority Index) with the aim of choosing minimum tardy jobs. Second, scheduling-rescheduling approach is used to tackle the dynamic environment of job-shop problem depending on three level algorithms. Third, proposing three level algorithms, these levels are resource level, process planning level to improve scheduling with the aim of minimizing tardy jobs and shorten "order-to-delivery", and job level to design rescheduling policy depending on identified factors of each job order. The developed model is applied to real data from the Heavy Engineering Equipment State Company/Baghdad, and considerable advantages are observed. Applying the proposed model lead to zero number of tardy jobs (NT) and zero mean tardiness (MT). It is obvious from the obtained results that by adopting such model, a better solution for job orders' due dates can be achieved; hence "order-to-delivery" time can be shortene

Metoclopramide protection of diazinon-induced toxicosis in chickens

The efficacy of metoclopramide for preventing organophosphate insecticide-induced (diazinon) toxicosis was evaluated in 7~14 days old chicks. Injection of metoclopramide at 25 mg/kg, s.c. 15 min before diazinon increased the oral 24 h median lethal dose of the insecticide in the chicks by 80%. Metoclopramide alone inhibited the in vitro and in vivo plasma and whole brain cholinesterase activities of the chicks. Metoclopramide pretreatment at 100 mg/kg, s.c. reduced the extent of cholinesterase inhibition that was caused by diazinon (10 mg/kg, p.o.) in the plasma and whole brain by 24% and 7%, respectively. Diazinon at 10 mg/kg, p.o. produced signs of cholinergic toxicosis in the chicks, and these signs included salivation, lacrimation, gasping and convulsions within 2 h, and the 2-h and 24-h lethalities were 88 and 100%, respectively. Metoclopramide at the dose rates of 12.5, 25, 50, 100 and 200 mg/kg, s.c. given 15 min before diazinon (10 mg/kg, p.o.) variably decreased the occurrence of toxic manifestations in the chicks. The highest dose of metoclopramide (200 mg/kg, s.c.) reduced the 2-h and 24-h lethality of diazinon to 75% each and it reduced the overall toxicity score of diazinon by 32%. The data suggest that metoclopramide pretreatment only partially protected chicks against the acute toxicity of diazinon

Experimental bond behaviour of GFRP and masonry bricks under impulsive loading

Fibre Reinforced Polymers have become a popular material for strengthening of masonry structures. The performance of this technique is strongly dependent on the bond between the FRP and the substrate. Understanding the strain rate effect on these materials and strengthening techniques is important for proper design and proper modelling of these systems under impacts or blast loads. This work aims to study the behaviour of the bond between GFRP and brick at different strain rates. A Drop Weight Impact Machine specially developed for pull-off tests (single shear tests) is used with different masses and different heights introducing different deformation rates. The strain rate effect on the failure mode, shear capacity and effective bond length is determined from the experimental results. Empirical relations of dynamic increase factors (DIF) for these materials and techniques are also presented.This work was performed under Project CH-SECURE (PTDC/EMC/120118/2010) funded by the Portuguese Foundation of Science and Technology – FCT. The authors acknowledge the support. The first author also acknowledges the support from his PhD FCT grant with the reference SFRH/BD/45436/2008

Plasma and whole brain cholinesterase activities in three wild bird species in Mosul, IRAQ: In vitro inhibition by insecticides

Plasma and brain cholinesterase activities were determined in three wild bird species to assess their exposure to organophosphate and carbamate insecticides which are used in agriculture and public health. In the present study, we used an electrometric method for measurement of cholinesterase activities in the plasma and whole brain of three indigenous wild birds commonly found in northern Iraq. The birds used were apparently healthy adults of both sexes (8 birds/species, comprising 3–5 from each sex) of quail (Coturnix coturnix), collard dove (Streptopelia decaocto) and rock dove (Columba livia gaddi), which were captured in Mosul, Iraq. The mean respective cholinesterase activities (Δ pH/30 minutes) in the plasma and whole brain of the birds were as follows: quail (0.96 and 0.29), collard dove (0.97and 0.82) and rock dove (1.44 and 1.42). We examined the potential susceptibility of the plasma or whole brain cholinesterases to inhibition by selected insecticides. The technique of in vitro cholinesterase inhibition for 10 minutes by the organophosphate insecticides dichlorvos, malathion and monocrotophos (0.5 and 1.0 µM) and the carbamate insecticide carbaryl (5 and10 µM) in the enzyme reaction mixtures showed significant inhibition of plasma and whole brain cholinesterase activities to various extents. The data further support and add to the reported cholinesterase activities determined electrometrically in wild birds in northern Iraq. The plasma and whole brain cholinesterases of the birds are highly susceptible to inhibition by organophosphate and carbamate insecticides as determined by the described electrometric method, and the results further suggest the usefulness of the method in biomonitoring wild bird cholinesterases

Experimental study of the bond strength between steel substrate and CFRP under impact tensile loads

Carbon fibre reinforced polymer (CFRP) has attracted a great deal of attention for upgrading and/or rehabilitating steel structures following its successful application for the strengthening of concrete structures. It is vital to maintain a sound bond between the CFRP and the steel substrate during service by selecting appropriate adhesives. The effect of dynamic loading (e.g. impact) on such bond is not well understood. This paper describes an experimental investigation of the efficiency of the bond between steel and normal modulus CFRP sheets under dynamic tensile loads of various loading speeds. The pull-off adhesion testing method was adopted. It was found that significant enhancement in adhesion bond strength for two types of resins was achieved at high strain rates. The failure mechanisms of both adhesives were remarkably influenced by speeds of loading and they illustrated noticeable changes compared to static loads

Numerical simulation of the dynamic behaviour of bond between CFRP sheet and steel

In recent years, the application of adhesively bonded carbon fibre reinforced polymer (CFRP) technique has attracted a considerable attention to retrofit and/or strengthen metal structures following its successful utilisation in upgrading concrete structures. Expensive cost and time consuming are the main drawbacks associated with conducting experimental tests. Thus, these shortcomings highlight the importance of developing finite element models too predict the bond behaviour between CFRP sheet and the strengthened steel element. This paper presents the experimental and numerical findings of axially loaded steel plates strengthened with CFRP sheet at static and dynamic loadings. ABAQUS software was adopted using three-dimensional models for both analyses. The parameters studied include the ultimate joint capacity, effective bond length and failure mode at different loading speeds (quasi-static and 3.35m m/s). It was found that the finite element results of all the studied variables are in good agreement with those observed experimentally