Toksikološke metode otkrivanja opojnih droga u tragovima: kromatografska, spektroskopska i biološka karakterizacija derivata ecstasyja

Analysis often reveals variability in the composition of ecstasy pills from pure 3,4-methylenedioxymethamphetamine (MDMA) to mixtures of MDMA derivatives, amphetamine, and other unidentifi ed substances. For a comprehensive toxicological analysis one needs to know all steps to MDMA synthesis which may originate impurities. The aim of this study was to synthesise and determine the chemical-physical and in vitro biological properties of a series of MDMA derivatives. 3,4-methylendioxyphenyl-2-nitropropene (MDNP) was obtained by condensation of piperonal with an excess of nitroethane in the presence of ammonium acetate. MDNP was then reduced to methylenedioxyamphetamine (MDA) by LiAlH3. All compounds were analysed using HPLC and spectroscopic technique [Raman, nuclear magnetic resonance (NMR), or infrared (IR)] at all the steps of synthesis. In addition, we assessed the biological potentials of these compounds by measuring in vitro their (i) blood cell/whole blood partition coeffi cient, (ii) binding to plasmatic proteins (Fbp), and (iii) membrane adsorption. Chemical structure was determined with antibody fl uorescence polarisation immunoassay (FPIA). This study showed the presence of solid impurities, particularly of a neurotoxic compound of Al3+ in the fi nal products. FPIA identifi ed the aminoethane group close to the substituted benzene ring, but did not detect the two major precursors of MDMA: MDNP and piperonal. Raman spectroscopy is an attractive alternative technique to characterise ecstasy pills and it can identify stereoisomeric forms such as cis-MDNP and trans-MDNP, which exhibit signals at 1650 cm-1 and 1300 cm-1, respectively.Analize često otkriju neujednačenost sastava tableta ecstasyja od čistoga 3,4-metilendioksimetamfetamina (MDMA) do mješavina njegovih derivata, amfetamina i drugih neutvrđenih tvari. Stoga je za kvalitetnu toksikološku analizu potreban uvid u sve korake sinteze MDMA, s obzirom na to da se ondje vjerojatno kriju izvori nečistoće (prekursori, katalizatori). Cilj ovog ispitivanja bio je sintetizirati derivate MDMA te napraviti njihovu kemijsko-fi zikalnu i biološku in vitro karakterizaciju. 3,4-metilendioksifenil-2-nitropropen (MDNP) dobiven je kondenzacijom piperonala u suvišku nitroetana uz dodatak amonijeva acetata. Njegovom redukcijom s pomoću LiAlH3 dobiven je 3,4-metilendioksiamfetamin (MDA). Svi spojevi iz pojedinih koraka sinteze karakterizirani su s pomoću tekućinske kromatografi je visoke djelotvornosti (HPLC) i spektroskopskih tehnika [Ramanove spektroskopije, nuklearne magnetske rezonancije (NMR-a) te infracrvene spektroskopije (IR-a)]. Usto je ocijenjen i njihov biološki učinak in vitro mjerenjem (i) koefi cijenta raspodjele krvna stanica/puna krv, (ii) vezanja za bjelančevine u plazmi (Fbp) te (iii) adsorpcije na membranu. Kemijska je struktura utvrđena s pomoću fl uorescentnoga polarizacijskog imunokemijskog testa (FPIA). Analiza je u konačnim proizvodima utvrdila prisutnost krutih nečistoća, napose spojeva neurotoksičnog aluminija (Al3+). FPIA je prepoznao aminoetansku skupinu blizu supstituiranoga benzenskog prstena, ali ne i dva glavna prekursora za MDMA: MDNP i piperonal. Posebno je zanimljiva Ramanova spektroskopija budući da (i) pruža privlačnu alternativu za karakterizaciju sastava tableta ecstasyja te (ii) može otkriti stereoizomerne cis/trans-oblike spoja poput cis-MDNP-a odnosno trans-MDNP-a, čiji se signal vidi na 1650 cm-1 odnosno 1300 cm-1

Évaluation des niveaux d’exposition et des effets sur la santé des travailleurs exposés aux poussières de bois dans la région de Sidi-Bel-Abbès en Algérie

ObjectifL’objectif de notre enquête est d’évaluer les risques et les niveaux d’exposition aux poussières de bois inhalables chez les travailleurs du bois. Méthode Une enquête descriptive de type transversal a été menée sur une période de sept mois allant de novembre 2007 à mai 2008, auprès des 100 menuiseries recensées au niveau de la wilaya de Sidi-Bel-Abbès. Seulement 87 entreprises ont répondu positivement à notre enquête, dont l’effectif total est de 620 menuisiers. La population étudiée est constituée de 400 artisans menuisiers, exclusivement de sexe masculin répondant au critère majeur d’inclusion à savoir ayant plus de 70 % de leurs temps annuels de travail en atelier. Les menuisiers en pose seule ainsi que les apprentis ont été exclus de notre étude. Un questionnaire médical pour chaque salarié et un questionnaire technique au niveau de chaque entreprise ont été remplis par le même médecin du travail chargé de l’enquête, cela nous a permis une meilleure connaissance des pratiques de ces salariés et d’établir un score d’exposition. La saisie et l’analyse des données ont été faites avec SPSS.11.5. Résultats Un risque collectif moyen a été évalué par le calcul des scores par entreprise. Les entreprises ont été classées en trois catégories de risque : fort–moyen–faible. L’âge moyen était de 39,11 ± 1,19 ans, l’ancienneté moyenne au poste est de 17,75 ± 0,98 ans. Les fumeurs représentaient 33,3 % de notre population dont 38,34 % supérieurs à 10 PA et avec 55 % des menuisiers qui travaillaient le bois dur. Les aspirations sur machines fixes existaient seulement dans 28 % versus 3 % sur machines portatives et uniquement 27 % des travailleurs utilisaient des moyens de protection individuels. L’obstruction nasale restait le signe le plus rapporté à 59 %. Conclusion Les scores laissent prévoir un empoussièrement excessif. Les signes irritatifs et allergiques sur le tractus des voies aériennes supérieures ont été observés. Axant nos priorités sur la prévention et la sensibilisation des menuisiers

UV-induced modification of stress distribution in optical fibers and its contribution to Bragg grating birefringence

This paper discusses the importance of stress-induced contributions to the photo-induced birefringence observed in fiber Bragg gratings. Optical tomography measurements are performed in exposed and unexposed fibers to extract the stress profiles induced by UV-writing of fiber Bragg gratings for various exposure levels. A photoelastic analysis and a high-order isoparametric finite elements method are then used to calculate the birefringence caused by stress profile modifications. The results are compared to the birefringence directly measured by spectral analysis of a chirped fiber grating with multiple phase-shifts. We can therefore estimate the fraction of the photo-induced birefringence due to stress-induced anisotropy following UV exposure. © 2008 Optical Society of America

Impact of heavy hole-light hole coupling on optical selection rules in GaAs quantum dots

We report strong heavy hole-light mixing in GaAs quantum dots grown by droplet epitaxy. Using the neutral and charged exciton emission as a monitor we observe the direct consequence of quantum dot symmetry reduction in this strain free system. By fitting the polar diagram of the emission with simple analytical expressions obtained from k$\cdot$p theory we are able to extract the mixing that arises from the heavy-light hole coupling due to the geometrical asymmetry of the quantum dot.Comment: 4 pages, 2 figure

Fermat-linked relations for the Boubaker polynomial sequences via Riordan matrices analysis

The Boubaker polynomials are investigated in this paper. Using Riordan matrices analysis, a sequence of relations outlining the relations with Chebyshev and Fermat polynomials have been obtained. The obtained expressions are a meaningful supply to recent applied physics studies using the Boubaker polynomials expansion scheme (BPES).Comment: 12 pages, LaTe

High-level cefotaxime-resistant Proteus mirabilis strain isolated from a Tunisian intensive care unit ward: CTX-M-8 extended-spectrum β-lactamase coproduced with a plasmid mediated AmpC lactamase

The aimed of this study was to determine the implication of the biochemical and the molecular mechanism and to describe the properties of an extended-spectrum β-lactamase (ESBL) CTX-M-8 which was reported for the first time in Africa. A clinical isolate of Proteus mirabilis FS6449 was isolated from a patient hospitalized at an intensive care unit of the Military Hospital in Tunisia in 2009. Antimicrobial susceptibility was determined with the disk diffusion method according to Clinical and Laboratory Standards Institute (CLSI) guidelines and revealed that this strain was resistant to expanded-spectrum β-lactams. Analysis of P. mirabilis FS6449 by double-disk synergy test yielded a positive result suggesting the production of ESBLs. Sonicate of the isolate hydrolysed cefotaxime and benzylpenicillin. Isoelectric focusing exhibited four β-lactamase bands of isoelectric points (pIs) 5.6, 6, 6.5 and over 7.6. Polymerase chain reaction (PCR) and sequencing experiments revealed the presence of four β-lactamase genes encoding TEM-2, CTX-M-8, TEM-24, and an AmpC enzyme. Among them, the genes encoding TEM-24 and an AmpC enzyme were transferred to the recipient by conjugation experiments.Keywords: Resistance, β-lactamase, Proteus mirabilisAfrican Journal of Biotechnology Vol. 12(21), pp. 3278-328

ANALYSE ECO-BOTANIQUE COMPARATIVE DE DEUX POPULATIONS DU Pistacia atlantica EN ALGERIE PAR LE BIAIS DE MARQUEURS MORPHOLOGIQUES FOLIAIRES

RESUME La sauvegarde des écosystèmes forestiers et steppiques passe nécessairement par la connaissance des exigences écophysiologiques des genres et espèces qui y sont largement présents. Parmi ces espèces, nous citons Pistacia atlantica (pistachier de l’Atlas), ce dernier est adapté aux différentes conditions climatiques et se caractérise par une grande plasticité. Cette étude se propose d’identifier cette espèce rustique dans son milieu naturel et permet également d’apporter les premiers éléments de réponses sur son comportement adaptatif vis-à-vis de l’environnement. Ce travail vise à établir une étude descriptive macro-morphologique de Pistacia atlantica, provenant de deux stations localisées sous différents bioclimats en Algérie, avec une analyse de la variabilité morphologique intra et inter-populations par l’utilisation d’un total de 15 caractères quantitatifs et qualitatifs morphologiques des feuilles dans le but d’identifier et de mieux connaitre l’espèce, ce qui permet de conserver la diversité génétique de cette espèce autochtone qui reste méconnue et par conséquent très peu employée dans la préservation des écosystèmes forestiers et pré-forestiers malgré ses intérêts, aussi bien écologique qu'économique. L’analyse statistique a permis de séparer les populations étudiées en deux groupes selon les variables étudiées et les conditions climatiques. Les dimensions des feuilles, le nombre de paires de folioles, longueur du pétiole, la forme de la foliole terminale, la forme du pétiole et la présence de trichomes, sont les caractéristiques les plus discriminantes. De même, les différentes adaptations observées lors de cette étude (variation dans la taille des feuilles) peuvent s’expliquer par la plasticité et la présence de cette espèce dans diverses conditions climatiques.   Mots clES: Algérie, feuille, macromorphologie, micromorphologie, Pistacia, trichomes, variabilité.   ABSTRACT The protection of the forest and steppe ecosystems takes place inevitably by the knowledge of the genus and the species ecophysiological requirements which are widely present there. Among these species, we quote Pistacia atlantica (Atlas pistachio), which is adapted to the various weather conditions and is characterized by its big plasticity. This study suggests identifying this rustic species in its natural environment and also provides the first elements of answers on its adaptive behavior towards the environment. This work aims at establishing a macro-morphological descriptive study of Pistacia atlantica, resulting from two stations located under various bioclimates in Algeria, with an analysis of morphological variability intra and inter-populations using a total of 15 quantitative and qualitative morphological characters of leaves with the aim of identifying and knowing better the species, which make it possible to preserve the genetic diversity of this native and autochthonous species which remains underestimated and consequently very little used in the conservation of the forest and pre-forest ecosystems in spite of its interests, so ecological as economic. The statistical analysis allowed to separate the populations studied in two groups according to the studied variables and the weather conditions. The size of leaves, number of pairs of sepals, length of the petiole, shape of the terminal sepal, shape of the petiole and the presence of trichomes, are the most discriminating characteristics. Also, the various adaptations observed during this study (variation in the size of leaves) can be understandable by the plasticity and the presence of this species in various climatic conditions

A comparison of electrochemical degradation of phenol on boron doped diamond and lead dioxide anodes

This work compares two electrode materials used to mineralize phenol contained in waste waters. Two disks covered with either boron doped diamond (BDD) or PbO2 were used as anodes in a one compartment flow cell under the same hydrodynamic conditions. Efficiencies of galvanostatic electrolyses are compared on the basis of measurements of Total Organic Carbon (TOC) and Chemical Oxygen Demand (COD). Galvanostatic electrolyses were monitored by analysis of phenol and of its oxidation derivatives to evaluate the operating time needed for complete elimination of toxic aromatics. The experimental current efficiency is close to the theoretical value for the BDD electrode. Other parameters being equal, phenol species disappeared at the same rate using the two electrode materials but the BDD anode showed better efficiency to eliminate TOC and COD. Moreover, during the electrolysis less intermediates are formed with BDD compared to PbO2 whatever the current density. A comparison of energy consumption is given based on the criterion of 99% removal of aromatic compounds

Efficient Delivery of Hydrophilic Small Molecules to Retinal Cell Lines Using Gel Core-Containing Solid Lipid Nanoparticles

In this study, we developed a novel solid lipid nanoparticle (SLN) formulation for drug delivery of small hydrophilic cargos to the retina. The new formulation, based on a gel core and composite shell, allowed up to two-fold increase in the encapsulation efficiency. The type of hydrophobic polyester used in the composite shell mixture affected the particle surface charge, colloidal stability, and cell internalization profile. We validated SLNs as a drug delivery system by performing the encapsulation of a hydrophilic neuroprotective cyclic guanosine monophosphate analog, previously demonstrated to hold retinoprotective properties, and the best formulation resulted in particles with a size of ±250 nm, anionic charge > −20 mV, and an encapsulation efficiency of ±60%, criteria that are suitable for retinal delivery. In vitro studies using the ARPE-19 and 661W retinal cell lines revealed the relatively low toxicity of SLNs, even when a high particle concentration was used. More importantly, SLN could be taken up by the cells and the release of the hydrophilic cargo in the cytoplasm was visually demonstrated. These findings suggest that the newly developed SLN with a gel core and composite polymer/lipid shell holds all the characteristics suitable for the drug delivery of small hydrophilic active molecules into retinal cells