Preparation and characterization of carbopol/silver nanoparticles composites obtained by heating process for antimicrobial application

Properties such as absorption, structural and external aspect of Carbopol/silver nanoparticles composites, prepared in DMF by heating process up to 30, 60, 80, 100 and 120 °C, were investigated by UV-visible, FTIR and SEM-EDS analyses. Samples were named respectively D30 to D120, according to the temperature at which they were extracted. The results showed that instead of the appearance of silver aggregates observed by SEM microscopy, all the obtained materials present a single absorption band centred at 430 nm, attributed to the classical surface plasmon excitation of the silver nanoparticles. The presence of silver nanoparticles is also proved by the X-ray powder diffraction XRD patterns, which show the appearance of small peaks corresponding to the face centered cubic (f.c.c.) silver phase in the case of D100 and D120 samples. Additionally strong interactions between silver ions and carboxylic groups of Carbopol were identified by ATR-FTIR spectroscopy. The thermal properties of the carbopol are effectively enhanced by the presence of silver nanoparticles as evidenced by thermo-gravimetric analysis. Furthermore the water loss that generally occurs at 100 °C in acrylic acid polymer was completely avoided in these new materials since less than 2 % of weight loss is recorded up to 160 °C. Finally, the inhibiting activity of Carbopol/silver nanoparticles composites against staphylococcus Aureus micro-organisms was confirmed for all the obtained materials, suggesting their suitable uses as effective growth inhibitors of micro-organisms and making them appropriate for diverse antimicrobial control systems

Retrospective study of epidemiological, clinicopathological and biological profils of 62 colorectal cancers cases in Jijel provence (Algeria)

In Algeria, the CRC wing and become the first digestive cancer in both sexes,  outperforming stomach cancer. To enrich the Algerian cancer registries, we analyzed the profiles of patients with these cancers in Jijel Willaya. This was a retrospective and descriptive analysis of epidemiological, clinicopathological and biological profiles of 62 CRC cases. We found that the CRC represented the first type of digestive cancers in which the three quarters were colon cancers. The most affected age group was 60-70 years with a male predominance and an average age of 56.20 years. The bleeding and abdominal pain were the majority telltale signs. The combined chemotherapy has been standardized with all patients and the Lieberkühnien adenocarcinoma was the major histological form. The disease issue and the choice of therapy depended on the K-RAS gene mutations. Our results were often compatible with the available literature and may provide reliable and relevant data on this disease.Key words: Colorectal cancer; Epidemiology; Therapy; Adenocarcinoma; K-RAS gen

Structure and Microstructure Properties of Ball Milled Fe-Zn

Nanocrystalline Fe10 %Zn and Fe30 %Zn alloys have been prepared from pure elemental powders by mechanical alloying processing in a high energy planetary ball-mill. Microstructural, structural, and magnetic characterizations of the powders were investigated by X-ray diffraction, and vibrating sample magnometer. The crystallite size reduction to the nanometer scale is accompanied by an increase in the atomic level strain. The reaction between Fe and Zn leads to the formation of a bcc Fe(Zn) solid solution with a lattice parameter close to (0.2912 nm for Fe30 %Zn and 0,2885 nm for Fe10 %Zn) after 5 h of milling. The complete dissolution of the elemental Zn powders in the a-Fe lattice gives rise to the formation of a highly disordered Fe(Zn) solid solution, where a-Fe(Zn) nanograins have a crystallite size of (229,29 Å for Fe10 %Zn (24 h) 30,09 Å for Fe30 %Zn (24 h), on prolonged milling time. The coercivity and magnetization values are 18,90 (Fe10 %Zn)Oe and 26,59 (Fe30 %Zn) emu/g, respectively, after 24 h of milling. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3514

Causality and the semantics of provenance

Provenance, or information about the sources, derivation, custody or history of data, has been studied recently in a number of contexts, including databases, scientific workflows and the Semantic Web. Many provenance mechanisms have been developed, motivated by informal notions such as influence, dependence, explanation and causality. However, there has been little study of whether these mechanisms formally satisfy appropriate policies or even how to formalize relevant motivating concepts such as causality. We contend that mathematical models of these concepts are needed to justify and compare provenance techniques. In this paper we review a theory of causality based on structural models that has been developed in artificial intelligence, and describe work in progress on a causal semantics for provenance graphs.Comment: Workshop submissio

Magnetic and Structural Properties of the Nanostructured Cu50Ni50 Powders

International audienc

Investigation of the critical behavior and magnetocaloric properties in the nanocrystalline CuNi powders

International audienc

X-ray diffraction, Mössbauer spectrometry and thermal studies of the mechanically alloyed (Fe 1−x Mn x ) 2 P powders

International audienc

Critical behavior, magnetic and magnetocaloric properties of melt-spun Ni50Mn35Sn15 ribbons

International audienc

Characterization of Polyphenols and Volatile Compounds from Understudied Algerian Pallenis spinosa by HS-SPME-GC-MS, NMR and HPLC-MSn Approaches

Pallenis spinosa (L.) Cass. is a widespread plant in the Mediterranean region. Traditionally, it is used as a medicinal species to treat several ailments, from inflammation to skin injuries. Although the phytochemical content of this plant has already been investigated, there is currently limited data on Algerian P. spinosa. In this work, we focused on volatile compounds and non-volatile secondary metabolites extracted using HS-SPME and methanol from the aerial parts of P. spinosa collected from Northeast Algeria. Volatile constituents were analyzed by GC-MS, while non-volatile compounds were analyzed by NMR and HPLC-MSn. In total, 48 volatile compounds were identified, including sesquiterpene hydrocarbons (65.8%), monoterpene hydrocarbons (16.9%), and oxygenated monoterpenes and sesquiterpenes (8.3% and 6.5%, respectively). β-Chamigrene (16.2%), α-selinene (12.8%), β-pinene (10.6%), and β-caryophyllene (9.2%) were assessed as the main constituents. Concerning non-volatile metabolites, 23 polyphenols were identified (7.26 mg/g DW), and phenolic acids were predominant (5.83 mg/g DW). Tricaffeoylhexaric acid (1.76 mg/g DW), tetracaffeoylhexaric acid (1.41 mg/g DW), 3,5-dicaffeoylquinic acid (1.04 mg/g DW), caffeoyl dihexoside (0.35 mg/g DW), and chlorogenic acid (0.29 mg/g DW) were the most abundant ones. Several known flavonoids, such as tricin and patuletin glycosides, kaempferol, and apigenin, were also identified, and myricetin hexoside was detected in P. spinosa for the first time. Overall, our work is the first to report an exhaustive characterization of volatile and non-volatile secondary metabolites from Algerian P. spinosa. The results represent a step forward in revealing the chemistry of this widespread plant species. Furthermore, they may contribute to rationalizing its traditional medicinal applications and preserve the biodiversity of Algerian flora

Microstructural, Hyperfine, and Magnetic Properties of FeSiBCuNb Deposits

International audienc