Manifestations cutanées au cours des giardioses: A propos de quelques cas cliniques

International audienceAbout three clinics cases, the author points out the presence of urticaria symptoms associated with giardiasis disease, and necessity of the treatment of such parasitosis, after parasitological investigation of motions.a propos de trois cas cliniques, l'auteur souligne l'existence de manifestations cutanées urticariennes au cours des giardoses à Giardia intestinalis, et la nécessité de traiter ce type de parasitose, après examen parasitologique des selle

Écologie des Leishmanioses dans le sud de la France

Poursuivant l’analyse structurale du foyer cévenol de leishmaniose viscérale, les auteurs procèdent à l’étude enzymatique de 47 souches isolées de cas humains (7 enfants, 7 adultes) et canins (33). Huit systèmes, liés au cycle respiratoire, sont éprouvés selon la technique de l’électrophorèse en gel d’amidon : PGM (E.C.2.7.5.1) ; PGI (E.C.5.3.1.9) ; G-6-PDH (E.C.1.1.1.49) ; 6-PGDH (E.C.1.1.1,44) ; IDH (E,C, 1.1.1.42) ; MDH (E.C.1.1.1.37) ; ME (E.C.1.1.1.40) ; GOT (E.C.2.6,1.1), Les zymogrammes obtenus sont semblables pour la totalité des échantillons. Une souche, isolée d’un cas de leishmaniose cutanéo-muqueuse, entre également dans ce groupe. En outre, aucune différence n’est constatée entre les échantillons cévenols et ceux provenant de souches viscérales canines d’origine niçoise, corse et tunisienne. De même, s’avère identique le zymogramme d’une souche isolée d’une leishmaniose viscérale du Honduras (Leishmania chagasi Cunha et Chagas, 1937). Par contre, une divergence est notée avec les zymodèmes correspondant aux formes viscérales indiennes et irakiennes (2 systèmes/8). Les arguments en faveur de l’individualité et de l’homogénéité du « macrofoyer » zoonotique méditerranéen se trouvent ainsi renforcés. Dès lors, pour ce foyer, le binôme Leishmania infantum Nicolle, 1908 est recommandé à la place de Leishmania donovani (Laveran et Mesnil, 1903), pour nommer le parasite responsable des formes viscérales, tant humaines que canines, et de certaines formes muqueuses humaines. Par voie de conséquence, Leishmania chagasi deviendrait synonyme de Leishmania infantum

Triazine-Substituted Zinc Porphyrin as an Electron Transport Interfacial Material for Efficiency Enhancement and Degradation Retardation in Planar Perovskite Solar Cells

Motivated by the excellent electron-transfer capability of porphyrin molecules in natural photosynthesis, we introduce here the first application of a porphyrin compound to improve the performance of planar perovskite solar cells. The insertion of a thin layer consisting of a triazine-substituted Zn porphyrin between the TiO2 electron transport layer and the CH3NH3PbI3 perovskite film significantly augmented electron transfer toward TiO2 while also sufficiently improved the morphology of the perovskite film. The devices employing porphyrin-modified TiO2 exhibited a significant increase in the short-circuit current densities and a small increase in the fill factor. As a result, they delivered a maximum power conversion efficiency (PCE) of 16.87% (average 14.33%), which represents a 12% enhancement compared to 15.01% (average 12.53%) of the reference cell. Moreover, the porphyrin-modified cells exhibited improved hysteretic behavior and a higher stabilized power output of 14.40% compared to 10.70% of the reference devices. Importantly, nonencapsulated perovskite solar cells embedding a thin porphyrin interlayer showed an elongated lifetime retaining 86% of the initial PCE after 200 h, while the reference devices exhibited higher efficiency loss due to faster decomposition of CH3NH3PbI3 to PbI2. © 2018 American Chemical Society

Lithium Doping of ZnO for High Efficiency and Stability Fullerene and Non-fullerene Organic Solar Cells

We report on the effect of lithium doping of zinc oxide used as electron-transport layer in organic solar cells based on both fullerene and non-fullerene acceptors. The experimental and theoretical results indicate that lithium ions intercalated within the ZnO lattice as dopants replace interstitial zinc defects that act as trap states and give rise to a higher electron conductivity without significantly altering work function and valence band edge. The enhanced electron carrier extraction/collection efficiency, the suppressed bimolecular and interface trap-assisted recombination losses and the higher electron mobility of the photoactive blend synergistically contribute to the superior performance of PTB7-Th:PC71BM-based fullerene devices utilizing doped ZnO layers with an optimized lithium concentration of 5 wt %. Such devices increased their maximum PCE from 8.59% (average 8.05%) to 10.05% (average 9.53%) while, simultaneously, boosting their long-term stability. Moreover, non-fullerene solar cells based on the PTB7-Th:IT-4F blend exhibited PCEs up to 8.96% and maintained more than 80% of their initial efficiency after 1000 h storage in the dark upon using the lithium modified ZnO electron transport layer. © 2019 American Chemical Society

A silanol-functionalized polyoxometalate with excellent electron transfer mediating behavior to ZnO and TiO2 cathode interlayers for highly efficient and extremely stable polymer solar cells

Combining high efficiency and long lifetime under ambient conditions still poses a major challenge towards commercialization of polymer solar cells. Here we report a facile strategy that can simultaneously enhance the efficiency and temporal stability of inverted photovoltaic architectures. Inclusion of a silanol-functionalized organic-inorganic hybrid polyoxometalate derived from a PW9O34 lacunary phosphotungstate anion, namely (nBu4N)3[PW9O34(tBuSiOH)3], significantly increases the effectiveness of the electron collecting interface, which consists of a metal oxide such as titanium dioxide or zinc oxide, and leads to a high efficiency of 6.51% for single-junction structures based on poly(3-hexylthiophene):indene-C60 bisadduct (P3HT:IC60BA) blends. The above favourable outcome stems from a large decrease in the work function, an effective surface passivation and a decrease in the surface energy of metal oxides which synergistically result in the outstanding electron transfer mediating capability of the functionalized polyoxometalate. In addition, the insertion of a silanol-functionalized polyoxometalate layer significantly enhances the ambient stability of unencapsulated devices which retain nearly 90% of their original efficiencies (T90) after 1000 hours. © 2018 The Royal Society of Chemistry

Engineering of Porphyrin Molecules for Use as Effective Cathode Interfacial Modifiers in Organic Solar Cells of Enhanced Efficiency and Stability

In the present work, we effectively modify the TiO2 electron transport layer of organic solar cells with an inverted architecture using appropriately engineered porphyrin molecules. The results show that the optimized porphyrin modifier bearing two carboxylic acids as the anchoring groups and a triazine electron-withdrawing spacer significantly reduces the work function of TiO2, thereby reducing the electron extraction barrier. Moreover, the lower surface energy of the porphyrin-modified substrate results in better physical compatibility between the latter and the photoactive blend. Upon employing porphyrin-modified TiO2 electron transport layers in PTB7:PC71BM-based organic solar cells we obtained an improved average power conversion efficiency up to 8.73%. Importantly, porphyrin modification significantly increased the lifetime of the devices, which retained 80% of their initial efficiency after 500 h of storage in the dark. Because of its simplicity and efficacy, this approach should give tantalizing glimpses and generate an impact into the potential of porphyrins to facilitate electron transfer in organic solar cells and related devices. © 2018 American Chemical Society