Diazoles y triazoles derivados del extracto de aceite de ricino: síntesis, efecto hipoglucémico, potencial antioxidante y actividad antimicrobiana

The ricinoleate triglyceride was extracted from castor-oil seeds grown in Algeria and isolated by catalytically methanolyse to methyl ricinoleate. Six diazole and triazole derivatives of ricinoleic acid were synthesized and characterized: 1,3,4-oxadiazole-5-thione (4); 1,3,4-thiadiazole-5-thione (5); 4-N-amino-1,2,4-triazole-5-thiol (7); 1,2,4-triazole-5-thione (9); 5-amino-1,3,4-oxadiazole (10) and 5-amino-1,3,4-thiadiazole (11). The antibacterial and antifungal screening data of synthesized compounds showed appreciable inhibition and among them, 5, 7 and 8 showed more inhibition on Gram positive Enterococcus faecalis than reference ampiciline; while compounds 1, 7, 8, 10 and 11 showed competitive antifungal effects compared to reference amphotericin B. In addition, all synthesized compounds (1-11) showed competitive antioxidant properties, particularly compounds 7 at 125, 250, 500 and 1000 μg/mL and compounds 4, 5 and 9 at a concentration of 1000 μg/mL. The intermediate compounds 1, 2 and 8 showed anti-α-amylase activity at various concentrations in the range of IC50 = (120.25 ± 1.17 - 130.42 ± 2.48). Oxadiazole 4 showed the best α-amylase inhibition by 78.5% at a concentration of 1000 μg/mL.Los triglicéridos de ricinoleico se extrajeron de semillas de aceite de ricino cultivadas en Argelia y se sintetizó catalíticamente con metanolisis el ricinoleato de metilo. Seis derivados de diazoles y triazoles de ácido ricinoleico se han sintetizado y caracterizado: 1,3,4-oxadiazol-5-tiona (4), 1,3,4-tiadiazol-5-tiona (5), 4-N-amino-1,2,4-triazol-5-tiol (7), 1,2,4-triazol-5-tiona (9), 5-amino-1,3,4-oxadiazol (10) y 5-amino-1,3,4-tiadiazol (11). Los datos de detección antibacteriana y antifúngica de los compuestos sintetizados mostraron una inhibición apreciable, entre ellos, los compuestos 5, 7 y 8 mostraron más inhibición en Enterococcus faecalis Gram positivo que la ampicilina de referencia. Mientras que los compuestos 1, 7, 8, 10 y 11 mostraron una influencia antifúngica competitiva en comparación con la anfotericina de referencia B. Como todos los compuestos sintetizados (1-11) mostraron propiedades antioxidantes competitivas, particularmente los compuestos 7, a 125, 250, 500 y 1000 μg/mL también compuestos 4, 5 y 9 a una concentración de 1000 μg/mL. Los compuestos intermedios 1, 2 y 8 mostraron actividad anti-α-amilasa a diversas concentraciones en el rango de IC50 = (120.25 ± 1.17 - 130.42 ± 2.48). El oxadiazol 4 mostró la mejor inhibición de la α-amilasa en un 78.5% a una concentración de 1000 μg/mL

Cognitive Radio Networks: Realistic or Not?

A large volume of research has been conducted in the cognitive radio (CR) area the last decade. However, the deployment of a commercial CR network is yet to emerge. A large portion of the existing literature does not build on real world scenarios, hence, neglecting various important interactions of the research with commercial telecommunication networks. For instance, a lot of attention has been paid to spectrum sensing as the front line functionality that needs to be completed in an efficient and accurate manner to enable an opportunistic CR network architecture. This is necessary to detect the existence of spectrum holes without which no other procedure can be fulfilled. However, simply sensing (cooperatively or not) the energy received from a primary transmitter cannot enable correct dynamic spectrum access. For example, the low strength of a primary transmitter's signal does not assure that there will be no interference to a nearby primary receiver. In addition, the presence of a primary transmitter's signal does not mean that CR network users cannot access the spectrum since there might not be any primary receiver in the vicinity. Despite the existing elegant and clever solutions to the DSA problem no robust, implementable scheme has emerged. In this paper, we challenge the basic premises of the proposed schemes. We further argue that addressing the technical challenges we face in deploying robust CR networks can only be achieved if we radically change the way we design their basic functionalities. In support of our argument, we present a set of real-world scenarios, inspired by realistic settings in commercial telecommunications networks, focusing on spectrum sensing as a basic and critical functionality in the deployment of CRs. We use these scenarios to show why existing DSA paradigms are not amenable to realistic deployment in complex wireless environments.Comment: Work in progres

Assessment of Calotropis natural dye extracts on the efficiency of dye-sensitized solar cells

ArticleThis work presents the construction and testing of solar cells sensitized with natural dyes extracted from plants indigenous to the desert. Calotropis plants are self - sufficient as they grow in very harsh environments, and yet are not consumed by humans or livestock due to their irritating agents to the skin and eyes. The energy generators of these plants are the leaves, which are crushed and processed to produce the dye solution. Also, the Calotropis leaves are covered in a white powder that is thought to aid in mitigating the heat by scattering incident radiation. This powder material is examined and added to the dye as it proved advantageous for the o verall cell efficiency, which reached 0.214% compared with 0.108% for cells with no powder. The produced cells are also compared with ones sensitized by spinach, another common natural sensitizer for dye - sensitized solar cells, and the performance proved t o be significantly better. The fact that Calotropis is a non - food plant is an added advantage to utilizing it as a dye source, along with its intrinsic heat resistance that allows it to survive the harsh desert conditions all year round

Preliminary study of haplotypes linked to the rare cystic fibrosis E1104X mutation

The analysis of some extra- and intragenic markers within or closely linked to the cystic fibrosis transmembrane regulator (CFTR) gene is useful as a molecular method in clinical linkage analysis. Indeed, knowing that the molecular basis of cystic fibrosis (CF) is highly heterogeneous in our population, the study of haplotype association with normal and CF chromosomes could be very helpful in cases where one or both mutations remain unidentified. In this study, we analysed with PCR-RFLP and capillary electrophoresis some extra (pJ3.11, KM19 and XV2C) and intragenic (IVS8CA, IVS17bTA and IVS17bCA) polymorphic markers in 50 normal and 10 Tunisian patients carrying the rare E1104X mutation in order to determine the haplotype associated with this mutation. For the extragenic markers, 8 haplotypes were identified. The most frequent of them are the 221 and 112 accounting for 80% of total haplotypes. For the intragenic markers, five haplotypes were present on the E1104X chromosomes. One of them 16-31-13 accounted for 50%. To our knowledge, this is the first work to be interested to the haplotypes linked to the E1104X mutation. This preliminary study of haplotypes could be a helpful method to determine the molecular lesions responsible of this pathology

Isotopic and velocity distributions of Bi produced in charge-pickup reactions of 208Pb at 1 A GeV

Isotopically resolved cross sections and velocity distributions have been measured in charge-pickup reactions of 1 A GeV 208Pb with proton, deuterium and titanium target. The total and partial charge-pickup cross sections in the reactions 208Pb + 1H and 208Pb + 2H are measured to be the same in the limits of the error bars. A weak increase in the total charge-pickup cross section is seen in the reaction of 208Pb with the titanium target. The measured velocity distributions show different contributions - quasi-elastic scattering and Delta-resonance excitation - to the charge-pickup production. Data on total and partial charge-pickup cross sections from these three reactions are compared with other existing data and also with model calculations based on the coupling of different intra-nuclear cascade codes and an evaporation code.Comment: 20 pages, 12 figures, background information on http://www-w2k.gsi.de/kschmidt

Localisation nasosinusienne des tumeurs plasmocytaires

Introduction : Les tumeurs plasmocytaires représentent 3 à 4% des tumeurs des cavités naso-sinusiennes. Elles nécessitent un bilan diagnostique spécifique et une prise en charge adéquate. Nous nous proposons d’étudier les particularités diagnostiques et thérapeutiques des plasmocytomes naso-sinusiens. Matériel et méthodes : Notre étude est rétrospective comportant 5 cas de plasmocytomes naso-sinusiens confirmés histologiquement.Résultats : Il s’agit de 3 hommes et 2 femmes âgés de 32 à 77 ans. Le plasmocytome avait une localisation sphénoïdale dans un cas, nasale dans 2 cas, ethmoïdo-nasale dans un cas et naso-maxillaire dans le cas restant. Il s’agissait d’un myélome multiple dans un cas. Trois patients ont eu une radiothérapie. Celle-ci était associée à une chimiothérapie dans le cas du myélome multiple et à une exérèse chirurgicale dans les 2 autres cas La chirurgie a été seule dans un cas. La chimiothérapie exclusive a été proposée dans un cas de plasmocytome localement avancé mais le patient a été perdu de vue. Pour les patients suivis, une seule récidive a été notée à 18 mois.Conclusion : La présentation clinique des plasmocytomes nasosinusiens est aspécifique. Le diagnostic est confirmé par l’histologie. Le pronostic est dominé par la présence ou non d’un myélome multiple et par la taille tumorale. Un suivi prolongé est nécessaire.Mots clés : plasmocytome extramédullaire ; cavités naso-sinusiennes ; radiothérapie ; chirurgie.Introduction: Plasmocytomas represent 3-4% of tumors naso-sinus cavities. Their diagnosis requires a specific investigations and adequate management. We report 5 cases of naso-sinus plasmacytoma and we propose to study their diagnostic and therapeutic characteristics.Materials and methods: Our study is retrospective including 5 cases of naso-sinus plasmacytoma confirmed histologically.Results: There were 3 men and 2 women aged 32 to 77 years. The plasmacytoma had a sphenoidal location in one case, nasal in 2 cases, ethmoid-nasal in one case and naso-maxillary in the remaining case. Multiple myeloma was found in one case. Three patients underwent radiotherapy. This was associated with chemotherapy in multiple myeloma case and surgical resection in 2 cases. Surgery alone was performed in one case. Exclusive chemotherapy was proposed in a case of plasmacytoma locally advanced but the patient was lost sight of. For followed patients, only one recurrence was noted at 18 months.Conclusion: The clinical presentation of sinonasal plasmacytomas is aspecific. The diagnosis is confirmed by histology. The prognosis is dominated by the presence or absence of multiple myeloma and tumor size. Prolonged follow-up is necessary.Keywords : extramedullary plasmacytoma, naso-sinus cavities, radiotherapy ; surgery