Design of Nanohydroxyapatite/Pectin Composite from Opuntia Ficus-Indica Cladodes for the Management of Microbial Infections.

Hydroxyapatite (HAp) attracts interest as a biomaterial for use in bone substitution or allografts. In the current work, biomaterial nanocomposites based on HAp and pectin were synthesized by using the double decomposition method, which involved using pectin extracted from fresh cladodes of the prickly pear, Opuntia ficus-indica. The crystallinity, purity, and several analytical techniques like Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy were used to understand the surface's shape. The results revealed that the produced HAp/pectin nanoparticles are pure, spherical, and amorphous. The spectroscopic data indicated a substantial interaction between HAp and pectin, specifically between Ca (II) and pectin hydroxyl and carboxyl groups. The presence of pectin showed a noticeable influence on the prepared nanocomposite texture and porosity. We further assess the antibacterial and antifungal activity of the developed nanocomposite against a number of pathogenic bacteria and fungi, evaluated by the well diffusion method. In the absence of pectin, the XRD analysis revealed that the HAp nanoparticles had 10.93% crystallinity. When the pectin concentration reached 10 wt.%, it was reduced to approximately 7.29%. All synthesized nanocomposites demonstrated strong antimicrobial activity against both Gram-positive (Staphylococcus aureus and Bacillus cereus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria in addition to various fungi (e.g., Aspergillus fumigatus, Penicillium funiculosum, and Trichoderma viride). This study endorses the HAp/Pectin nanocomposite as an efficient antimicrobial material for biomedical advanced applications.

Antibacterial activity and virtual screening by molecular docking of lycorine from Pancratium foetidum Pom (Moroccan endemic Amaryllidaceae).

Lycorine is an alkaloid isolated from bulbs of Pancratium foetidum Pom Amaryllidaceae of the genus Lycoris. It has very strong pharmacodynamics properties and biological effects, among others, antimalarial, antiviral, antitumor, and anti-inflammatory. Lycorine has been identified and characterized by thin layer chromatography, IR and NMR (1H and 13C NMR, COZY, HMBC, HSQC and NOESY). The antibacterial activity of lycorine has been evaluated. Lycorine has a moderate antibacterial activity on the majority of strains studied, nevertheless it is more effective than Streptomycin and Ampicillin against bacteria: P. aeruginosa, En. cloacae. To confirm these results, it is necessary to use qualitative techniques and methods, etc… We performed a virtual docking ligand-lycorine protein screening study to predict and characterize their mode of interaction with the LpxC receptor. Docking results have shown that lycorine can interact with target amino residues studied by hydrogen and metal-ion bonds. In addition, the ADME-Tox profile study has shown that lycorine is all in agreement, either with Lipinski's critics or with the toxicity standards.

Natural product based composite for extraction of arsenic (III) from waste water.

Natural based composites of hydroxyapatite/Gum Arabic designed for removal of toxic metal arsenic (III) from waste water were synthesized and evaluated. Several composites with various compositions were prepared by the wet chemical method and analyzed using various spectroscopic and analytical methods such as: Fourier transform infrared spectroscopy, total organic carbon production, XRD analysis and scanning electron microscope. The rates of weight loss and water absorption of the HAp/GA composites as a function of time were evaluated in phosphate-buffered saline solution at 37 °C and a pH of 7.4. The effects of several variables on adsorption of arsenic (III) by HAp/GA composites were evaluated. The variables include arsenic (III) concentration, contact time (t) and complex surface nature of HAp/GA composite. Three surface complexation models were used to study the mechanisms controlled the adsorption. The models were Langmuir, Freundlich and Dubinin Radushkevich. The adsorption kinetic of arsenic (III) on the composite surface was described by three modes: pseudo first order, pseudo second order and the intra particle diffusion. The results revealed that, the rate of adsorption of arsenic (III) by HAp/GA composites was controlled by two main factors: the initial concentration of arsenic (III) and the contact time. The kinetic studies also showed that, the rate of adsorption is a second order. The results indicate that, composite offered in this study could be a valuable tool for removing toxic metals for contaminated water by adsorption. Graphical abstract .

Vapor liquid solid-hydride vapor phase epitaxy (VLS-HVPE) growth of ultra-long defect-free GaAs nanowires: ab initio simulations supporting center nucleation.

High aspect ratio, rod-like and single crystal phase GaAs nanowires (NWs) were grown by gold catalyst-assisted hydride vapor phase epitaxy (HVPE). High resolution transmission electron microscopy and micro-Raman spectroscopy revealed polytypism-free zinc blende (ZB) NWs over lengths of several tens of micrometers for a mean diameter of 50 nm. Micro-photoluminescence studies of individual NWs showed linewidths smaller than those reported elsewhere which is consistent with the crystalline quality of the NWs. HVPE makes use of chloride growth precursors GaCl of which high decomposition frequency after adsorption onto the liquid droplet catalysts, favors a direct and rapid introduction of the Ga atoms from the vapor phase into the droplets. High influxes of Ga and As species then yield high axial growth rate of more than 100 µm/h. The diffusion of the Ga atoms in the liquid droplet towards the interface between the liquid and the solid nanowire was investigated by using density functional theory calculations. The diffusion coefficient of Ga atoms was estimated to be 3 × 10(-9) m(2)/s. The fast diffusion of Ga in the droplet favors nucleation at the liquid-solid line interface at the center of the NW. This is further evidence, provided by an alternative epitaxial method with respect to metal-organic vapor phase epitaxy and molecular beam epitaxy, of the current assumption which states that this type of nucleation should always lead to the formation of the ZB cubic phase.

Immunonutrition improves functional capacities in head and neck and esophageal cancer patients undergoing radiochemotherapy: a randomized clinical trial.

BACKGROUND & AIMS: Malnutrition is frequent in head and neck (HN) and esophageal cancer patients and aggravated by radiochemotherapy (RCT), increasing morbi-mortality and treatment toxicity. Our goal was to investigate the effect of immunonutrition consisting of an arginine, omega-3 fatty acid, nucleotides-enriched diet on nutritional status, and functional capacity in HN or esophageal cancer patients undergoing RCT. METHODS: 37 patients were randomized in a double-blind clinical trial. 5 days before and until the end of RCT (5-7 weeks), they received either an Immunomodulating Enteral Nutrition (IEN) or an isonitrogenous, isoenergetic Standard Enteral Nutrition (SEN). Anthropometrical parameters, nutritional risk index (NRI), serum albumin, plasma antioxidant capacity, and functional capacity were recorded between the beginning and the end of RCT. RESULTS: A significant gain in total body weight (+2.1 ± 3.1 kg) was observed in IEN patients. Albuminemia and NRI were improved concomitantly in IEN malnourished patients. Plasma antioxidant capacity was improved (+100 ± 13 µM EqTrolox) in IEN patients. Functional capacity measured by WHO Performance Status and Karnofsky index was maintained in IEN patients but significantly reduced in SEN patients. CONCLUSIONS: These preliminary data show that immunonutrition could improve the nutritional status together with functional capacity in HN and esophageal cancer patients undergoing RCT. CLINICAL TRIAL REGISTRATION: This clinical trial promoted by the University Hospital Center of Clermont-Ferrand has been registered at ClinicalTrial.gov website under the following reference: NCT00333099.

Fast growth synthesis of GaAs nanowires with exceptional length.

We report the first synthesis of GaAs nanowires (NWs) by Au-assisted vapor-liquid-solid (VLS) growth in the novel hydride vapor phase epitaxy (HVPE) environment. Forty micrometer long rodlike <111> monocrystalline GaAs nanowires exhibiting a cubic zinc blende structure were grown in 15 min with a mean density of 10(6) cm(-2). The synthesis of such long figures in such a short duration could be explained by the growth physics of near-equilibrium HVPE. VLS-HVPE is mainly based on solidification after direct and continuous feeding of the arsenious and GaCl growth precursors through the Au-Ga liquid catalyst. Fast solidification (170 microm/h) is then assisted by the high decomposition frequency of GaCl. This predominant feeding through the liquid-solid interface with no mass and kinetic hindrance favors axial rather than radial growth, leading to twin-free nanowires with a constant cylinder shape over unusual length. The achievement of GaAs NWs several tens of micrometers long showing a high surface to volume ratio may open the field of III-V wires, as already addressed with ultralong Si nanowires.

[Unusual disclosure of giant Meckel's diverticulum]. / Révélation inhabituelle d'un diverticule géant de Meckel.

At discovery of diabetes mellitus, complementary explorations revealed a superinfection of a giant Meckel's diverticulum. We present this clinical situation in one case and suggest possible nosologies. The epidemiology and clinical approach to Meckel's diverticulum are discussed.

[Toxocariasis and functional intestinal disorders. Presentation of 4 cases]. / Toxocarose et troubles fonctionnels intestinaux. Présentation de 4 cas.

We report 4 cases of adults patients, suffering from irritable bowel syndrome, which had been attributed late to toxocariasis and for whom the treatment led to recovery. Hypereosinophilia was present only in 3 cases. These cases show that toxocariasis is not limited anymore to its two classical expressions: visceral larva migrans and ocular toxocariasis. So it is useful to think of it to confirm and treat it in the case of patients suffering from irritable bowel syndrome. This enables shorter diagnosis delay (14 months in average for our patients) and this is essential for therapeutic efficiency.