368 research outputs found

    Study of the Chelating Ability of Hexane, Chloroform, Ethyl acetate and Methanolic Root Extracts from Algerian Phragmites australis Species

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    Introduction: Heavy metals that enter organisms can cause illness and disease. Chelation therapy is a solution that uses chelating agents to protect these organisms by high accumulation. Materials and methods: The objective of this study is to evaluate the capability of different roots extracts from reed or EDTA (as standard) to complexate iron using, ferrozine-ferrous reducing assay or Zn and Cu using the murexide-Zn or Cu reducing assay in vitro. Results: the results proved that the organic phase of the first extract and EDTA (standard chelator), have the strongest chelation activities with respective rates of 70% and 97% for iron, 55% and 56% for zinc and 47% and 88% for copper compared to the control groups considered to be 100% of the complexation. Finally, the HPLC analysis showed the presence of six organic acids, which are probably responsible for this effect. Conclusion: The hexane extract and EDTA (standard), have the strongest chelation activities. Keywords: Phragmites australis, Chelation, Heavy metals, Organic acids, Ferrozine, Murexide

    Problèmes de réalisabilité et de connexité dans les graphes chimiques

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    RÉSUMÉ : Cette maîtrise s’inscrit dans le domaine de la chimie mathématique, et plus précisément le domaine de la théorie des graphes chimiques. Ce domaine est en pleine expansion depuis les travaux de William Cullen en 1758. Plusieurs invariants chimiques liés à la théorie des graphes ont été étudiés tels que l’indice de Randic, ainsi que le premier et le second indice de Zagreb. On les regroupe aujourd’hui sous le nom d’indices Adriatiques. Plusieurs modèles mathématiques ont été développés pour déterminer des bornes inférieures et supérieures pour ces invariants chimiques, ainsi que les graphes extrêmes correspondants. Ces modèles ne prennent pas en compte la connexité des graphes, en ce sens qu’aucune contrainte de connexité n’est imposée sur les graphes extrêmes générés. Nos recherches ont porté sur le développement d’un algorithme capable de générer des graphes extrêmes simples (c’est-à-dire sans boucle ni arête multiple) et connexes atteignant la kème plus petite ou la plus grande valeur des indices Adriatiques (k � 1). Pour ce faire, nous avons déterminé des conditions nécessaires et suffisantes pour l’existence d’un graphe simple et connexe lorsque pour toute paire i, j d’entiers strictement positifs, on impose le nombre mij d’arêtes reliant les sommets de degré i à ceux de degré j. Nous avons ensuite montré qu’il est possible d’imposer ces conditions à l’aide d’un modèle linéaire en nombres entiers. Puis, nous avons utilisé ce modèle mathématique pour déterminer les valeurs extrêmes de plusieurs indices Adriatiques pour plusieurs familles de graphes, et nous avons finalement montré comment il est possible de générer les graphes qui atteignent ces valeurs. Mots clés : graphes chimiques, invariants adriatiques, programmation linéaire en nombres entiers, problèmes de connexité.----------ABSTRACT : This research lies is in the field of mathematical chemistry, and more specifically in the area of the theory of chemical graphs. This domain is in full expansion since the early works of William Cullen in 1758. Several graphical chemical invariants have been studied such as the Randic index, and the first and second Zagreb index. These invariants are known today as the Adriatic invariants. Several mathematical models have been developed to determine lower and upper bounds for these chemical invariants, as well as their corresponding extreme graphs. However, these models do not take connexity constraints into account, in that sense that it is not imposed that the generated extreme graphs should be connected. The main objective of my research was to develop an algorithm able to generate extreme simple (i.e., without loops of multiple edges) and connected graphs that reach the kth smallest ou largest value of Adriatic invariants (k � 1). For this purpose, we have first determined necessary and sufficient conditions for the existence of a simple connected graph when for every pair i, j of striclty positive integers, it is imposed that the generated graphs should have a fixed number mij of edges linking vertices of degree i with vertices of degree j. We have then shown that these conditions can be imposed by an integer programming model. The model was then used to determine extremal values of Adriatic indices for several families of graphs, and we have finally shown how to generate graphs that reach these values. Key words: Chemical graphs, Adriatic indices, linear integer programming, connectivity problems

    190: In how many patients with Wolff-Parkinson-White syndrome-related adverse presentation isoproterenol infusion was required to reproduce the arrhythmia?

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    Electrophysiological study is the main method for the detection of patients with a Wolff-Parkinson-White syndrome (WPW) at risk of adverse presentation (resuscitated ventricular fibrillation (VF), documented life-threatening arrhythmia): the protocol is debated. The purpose of the study was to look in how many patients with WPW-related adverse presentation, atrial fibrillation (AF) or atrial tachycardia with the shortest RR cycle length (CL) with 1/1 conduction over accessory pathway (AP)<250msec was induced in control state (CS) and when isoproterenol was required.Methods63 patients, mean age 38±18, were referred for WPW-related adverse presentation (VF 6, other 56). EPS included in CS atrial pacing and measurement of the shortest CL with 1/1 conduction over AP and programmed stimulation with 1 and 2 extrastimuli. AP effective refractory period (ERP) was determined. In absence of induction of a tachycardia with a CL <250msec, isoproterenol (0.02 to 1μg. min-1) was infused to increase sinus rate to 130bpm; the protocol was repeated.ResultsMean shortest CL conducted over AP was 223±30msec in CS, 192±25msec after isoproterenol. APERP was 225±29msec in CS, 191±19msec after isoproterenol. Atrioventricular orthodromic tachycardia (AVRT) was induced in 34 patients (54%), antidromic tachycardia (ATD) in 13 (21%), AF in 43 (68%). Criteria for a malignant form (induction of AF or ATD with a shortest CL <250mesc) were noted in 42 patients (67%) in CS and were obtained after isoproterenol in remaining 21 patients (33%). Among these patients, 12 had inducible tachycardia in CS (AVRT (n=6), ATD (n=3), AF (n=3) but the shortest CL was >240msec. A tachycardia was only induced after isoproterenol in 9 patients (14%).ConclusionsInfusion of isoproterenol should be systematic when WPW is evaluated. EPS performed only in CS missed at least 14% of patients at risk of life-threatening arrhythmias who had no inducible supraventricular tachyarrhythmia and 33% of patients with a WPW without the classical criteria for a malignant form. Isoproterenol increased the sensitivity of EPS for the detection of malignant form from 67 to 100%

    Validation Study of the Mini-Mental State Examination in Urdu Language for Pakistani Population

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    Validation study of the Mini-Mental State Examination in Urdu language for Pakistani population. Objective: This study was conducted primarily to validate and determine the optimal cutoff score in the diagnosis of dementia among Pakistani’s and study the effects of gender and education on the MMSE performance in our population. Methods: Four hundred participants took part in the study. Patient with dementia recruited from five major hospitals from Pakistan. The MMSE was translated into Urdu. Results: There were 61 men and 39 women in dementia group and 225 men and 75 women in the control group. The mean score of Urdu MMSE were lower in patients with dementia 18.5 ± 5.6 (range 0-30) as compared to the controls 26.8 ± 2.6 (range 7-30). This difference between groups was statistically significant (p\u3c0.001). Educational based MMSE score below 15 yielded perfect sensitivity and specificity for the diagnosis of dementia. Conclusions: These finding confirm the influence of level of education on MMSE score and education stratified cutoff scores should be used while screening for cognitive impairment in this population

    Validation Study of the Mini-Mental State Examination in Urdu Language for Pakistani Population

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    Validation study of the Mini-Mental State Examination in Urdu language for Pakistani population. Objective: This study was conducted primarily to validate and determine the optimal cutoff score in the diagnosis of dementia among Pakistani’s and study the effects of gender and education on the MMSE performance in our population. Methods: Four hundred participants took part in the study. Patient with dementia recruited from five major hospitals from Pakistan. The MMSE was translated into Urdu. Results: There were 61 men and 39 women in dementia group and 225 men and 75 women in the control group. The mean score of Urdu MMSE were lower in patients with dementia 18.5 ± 5.6 (range 0-30) as compared to the controls 26.8 ± 2.6 (range 7-30). This difference between groups was statistically significant (p\u3c0.001). Educational based MMSE score below 15 yielded perfect sensitivity and specificity for the diagnosis of dementia. Conclusions: These finding confirm the influence of level of education on MMSE score and education stratified cutoff scores should be used while screening for cognitive impairment in this population

    Etude de la mycoflore associée à Pyrus mamorensis Trabut, arbre endémique de la forêt de la Mamora (Maroc)

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    The investigations conducted in the Mamora forest have proved for the first time the presence of several species of fungi that infect different organs of Pyrus mamorensis Trabut endemic species of Morocco. Different species of fungi were isolated from lesions on leaves, flowers, buds and fruits. The foliar lesions contain a fungal complex: Aspergillus niger, A. fumigatus, Alternaria alternata, Cladosporium herbarum, Drechslera australiensis, Mucor sp, Rhizopus stolonifer, Epiccoccum nigrum, Trichoderma harzianum. Curvularia lunata and Aspergillus versicolor were isolated from the fruit. Fungi that are able to grow on the wood of the trunk of Pyrus mamorensis are: Hysterium pulicare, H. asymetricum and Trematosphaeria pertusa.Les prospections réalisées dans la forêt de la Mamora, ont révélé pour la première fois la présence de nombreux champignons qui infectent différents organes du poirier de Mamora (Pyrus mamorensis Trabut) espèce endémique du Maroc. Les isolements à partir des lésions au niveau des feuilles, fleurs, bourgeons et fruits ont permis d’identifier différentes espèces.Les lésions foliaires renferment un complexe fongique: Aspergillus niger, A. fumigatus, Alternaria alternata, Cladosporium herbarum, Drechslera australiensis, Mucor sp., Rhizopus stolonifer, Epiccoccum nigrum, Trichoderma harzianum. Curvularia lunata et Aspergillus versicolor ont été isolés à partir du fruit. Les champignons qui sont capables de se développer sur le bois du tronc de Pyrus mamorensis, sont : Hysterium pulicare, H. asymetricum et Trematosphaeria pertusa

    0034: Preexcitation syndrome and atrioventricular nodal reentrant tachycardia: coincidence or not?

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    BackgroundReciprocating tachycardia which occurs in patients with a preexcitation syndrome (PS) generally is directly related to the presence of the accessory pathway (AP) and is called atrioventricular re-entrant tachycardia (AVRT). The purpose of the study was to evaluate the incidence of re-entrant tachycardia of other nature among patients with a PS.Methods785 patients with paroxysmal tachycardia were admitted AP ablation, 294 patients with a concealed AP (group I) and 491 patients with a Wolff-Parkinson-White syndrome (WPW) (group II). Programmed atrial stimulation was performed in the control state and if necessary after isoproterenol to induce the clinical tachycardia and determine its mechanism.ResultsAVRT was induced in 760 patients (97%), 282 of group I (96%)and 478 of group II (97%) (NS). Atrioventricular nodal re-entrant tachycardia (AVNRT) was induced in 13 group I patients (4.6%) and 12 group II patients(2.5%) (NS; 0.11). In 9 group I patients (3%) and in 4 group II patients (1%) (p<0.015), both AVRT and AVNRT were induced. In patients with only induced AVNRT, slow pathway ablation was performed and accessory pathway was respected because there was no inducible tachycardia using AP and the conduction over AP was poor. These patients remained free of symptoms after ablation of AV node slow pathway. Among this population 3 families were identified as having either AVRT or AVNRT.ConclusionsIn patients with concealed or patent accessory pathway and complaining of paroxysmal tachycardia, a careful evaluation of the mechanism of tachycardia is required before ablation. Patients with concealed conduction over an AP have more frequently an association of AVRT and AVNRT than patients with a patent preexcitation syndrome. Rarely AVNRT can be the only mechanism of symptoms
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