A domino reaction of tetrahalo- 7,7-dimethoxybicyclo[2.2.1]heptenyl alcohols leading to indenones and a de novo synthesis of ninhydrin derivatives

An efficient acid induced rearrangement of a tetrahalo-7,7-dimethoxybicyclo[2.2.1]heptenyl system leading to substituted indenones is reported. This domino reaction involves dehydration, olefin isomerization, ketal hydrolysis, [3,3]-sigmatropic rearrangement and dehydrohalogenation. The resultant vicinal dihalo olefin moiety in the efficiently generated indenone derivatives was utilized to transform into ninhydrin derivatives by employing Ru(III)-catalyzed oxidation

Physicochemical characteristics and pollen spectrum of some north-east Algerian honeys.

The qualities of seventeen honey samples harvested from the North-East areas of Algeria were evaluated by determining the pollen spectrum, pollen number quantity and physicochemical attributes. Pollen analysis can therefore be useful to determine the geographical and botanical origin of honeys. The following determinations were carried out: pH, density, acidity (free, lactone and total), moisture, electrical conductivity,  hydroxymethylfurfural, diastase activity, apparent sucrose, and proteins.The results obtained in the present study show the variability of chemical composition of the honey samples. It proved that nine natural honeys are of blossoming origin; suitable for consumption and that one (T5 conferred Bougous) can be used with fine dietetics, it is very rich in pollen which is regarded as protein source. The remainder, eight honeys, were not in conformity with the International Regulatory Standards, their sugar contents (Sucrose) and hydroxymethylfurfural exceeded the InternationalRegulatory Standards Review by the International Honey Commission, this was probably due to use of syrup for the over-feeding the bees during the spring. The sample Bouhachana (G1) had high water content (more than 20%), low density and electrical conductivity higher than 5 μS/cm, which makes it likely to undergo fermentation and degradation. Honeys of Guerguour (T1), Boutheldja (T2) and Bouhadjar (T3) had pH lower than the European standards concerning the quality control of the foodstuffs (exp. honey). These samples are fragile; so we cannot preserve them for a long period. The palynological analysis (qualitative and quantitative) of the harvested samples in the area, showed the absence of a honey obtained from only one melliferous plant. All honeys are polyfloral exits of theseveral plant species visited by the worker bees during their blossoming periods. Three families are the most represented in the groups of pollen of accompaniment (the secondary pollen ranged between 16-45%) and the pollen considered as rare (minor pollen 3-15%) in the counted total number of the pollen grains in 10 grams of honey. These forager honey families are: Myrtaceae presented by the Eucalyptus, Papilionaceae presented by Hedysarum coronarium which is a forager plant characterized by a very vast surface of development, and Rosaceae represented byorchard and forest species.The pollen grain number counted in honeys is very significant (between 80 000 and 24 832 000pollen grain), what makes it possible to classify the samples analyzed among the categories rich in pollen

Modificación enzimática de fosfatidilcolina con n-3 PUFA a partir de ácidos grasos de aceites de gusanos de seda

α-Linolenic acid (ALA) containing phosphatidylcholine (PC) was prepared by an enzymatic method employing natural substrates comprising of egg and eri silkworm oil. Eri silkworm oil extracted from eri pupae was saponified to obtain the fatty acid mixture which was further subjected to urea complexation to obtain an ALA rich fraction with a purity of about 93%. Transesterification of PC with the ALA rich fraction with three immobilized lipases namely Lipozyme TL IM, Lipozyme RM IM and lipase from Candida Antarcticaz showed that only the lipase from Candida antarctica was successful for the incorporation of ALA into egg yolk PC. It was found that ALA was incorporated by up to 27% in the sn-1 position of egg PC and the positional distribution analysis of fatty acids in the modified PC showed that the sn-1 position was found to contain about 59% ALA.El ácido α-linolénico (ALA) contenido en fosfatidilcolina (PC) se preparó mediante un método enzimático empleando sustratos naturales que comprenden huevo y aceite de gusanos de seda. El aceite extraído de las crisálidas de gusanos de seda se saponificó para obtener la mezcla de ácidos grasos que se sometió a complejación con urea para obtener la fracción rica en ALA, con una pureza aproximadamente del 93%. La transesterificación de PC con fracción rica en ALA con tres lipasas inmovilizadas, Lipozyme TL IM, Lipozyme RM IM y lipasa de Candida antárctica, mostró que sólo la lipasa de Candida antarctica tuvo éxito en la incorporación de ALA en PC de yema de huevo. Se encontró que el ALA fue incorporado hasta 27% en la posición sn-1 de PC de huevo y el análisis de la distribución de los ácidos grasos en PC modificado mostró que la posición sn-1 que contenía aproximadamente 59% de ALA

Sensitivities of the Proton-Nucleus Elastical Scattering Observables of 6He and 8He at Intermediate Energies

We investigate the use of proton-nucleus elastic scattering experiments using secondary beams of 6He and 8He to determine the physical structure of these nuclei. The sensitivity of these experiments to nuclear structure is examined by using four different nuclear structure models with different spatial features using a full-folding optical potential model. The results show that elastic scattering at intermediate energies (<100 MeV per nucleon) is not a good constraint to be used to determine features of structure. Therefore researchers should look elsewhere to put constraints on the ground state wave function of the 6He and 8He nuclei.Comment: To be published in Phys. Rev.

Physical and mechanical characteristics of the earthen barns used for food crop storage in the North-West of Benin (West Africa)

Atacora and Donga are two departments regarded as the barns of Benin. In these two regions, the surplus of food crops harvested by farmers is stocked in earthen barns whose primary construction material is kneaded clay soil with an admixture of vegetable straws (fonio, rice…) pounded beforehand. The following research is designed to scrutinize the variation of compression strength and/or tensile strength of the used earthen material with respect to the optimum straw content, and the fluctuation of the fracture related parameters. Laboratory tests have shown that an optimum straw content of 2% provides the highest compression strength with the best mechanical performances in terms of cohesion and internal angle of friction. Tensile strength, however, continues to increase with higher straw percentages with no breakpoint indication. Moreover, the laboratory determination of the composite material’s modulus of elasticity has proven that the used soil does not have a linear elastic behavior

Specific crosslinking effects of poly(epichlorohydrin)-triol on urethane polymer matrix of castor seed oil-based coatings

The contributions of castor seed oil (CSO) as a useful, nontoxic, and sustainable base material for coating systems cannot be overemphasized. This paper took advantage of the predominant fatty acid composition in CSO (i.e., ricinoleic acid). It blended a synthesized crosslinker, poly(epichlorohydrin-triol) (PECH-triol), in percentages within its polymeric matrix. Physicochemical and spectroscopic (FTIR, 1H-NMR, and 13C-NMR) examinations were carried out on the polyols. Thermal stability, hydrophobicity, anticorrosion, mechanical, and antibacterial properties of the prepared polyurethane (PU) coatings were examined. The 20% PECH-triol–CSO-PU film having its TON and TEND at 230.5 and 511.0°C, respectively, showed improved thermal stability when compared with the pristine film (CSO-PU). The derivative of TGA reveals a three-stage degradation step. Hydrophobicity was seen to increase from 73.3° to 92.2°, a reflection of the crosslinking effect of PECH-triol within the urethane matrix. The improved adhesion of 20% PECH-triol–CSO-PU coating on mild steel gave a better chemical resistance

Pregabalin, celecoxib, and their combination for treatment of chronic low-back pain

Background - The efficacy and safety of the association of celecoxib [a selective cyclooxygenase-2 (COX-2) inhibitor] and pregabalin (commonly used to control neuropathic pain), compared with monotherapy of each, were evaluated for the treatment of chronic low-back pain, a condition known to be due to neuropathic as well as nociceptive pain mechanisms. Materials and methods - In this prospective randomized trial, 36 patients received three consecutive 4-week treatment regimes, randomly assigned: celecoxib plus placebo, pregabalin plus placebo, and celecoxib plus pregabalin. All patients were assessed by using a visual analogue scale (VAS, 0\u2013100 mm) and the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) pain scale by an investigator blinded to the administered pharmacological treatment. Results - Celecoxib and pregabalin were effective in reducing low-back pain when patients were pooled according to LANSS score. The association of celecoxib and pregabalin was more effective than either monotherapy in a mixed population of patients with chronic low-back pain and when data were pooled according to LANSS score. Adverse effects of drug association and monotherapies were similar, with reduced drug consumption in the combined therapy. Conclusions - Combination of celecoxib and pregabalin is more effective than monotherapy for chronic low-back pain, with similar adverse effects