Effect of acid treated HY zeolites in adsorption of mesosulfuron-methyl.

Purpose: Pollution of surface water and groundwater by bulky molecules such as pesticides has been recognized as a major problem in many countries due to their persistence in aquatic environment and potential adverse health effects. The main purpose of this study is the development of a capable adsorbent to remove these bulky molecules from wastewater such as the pesticide Mesosulfuron-Methyl (MM) by reducing the diffusion path, to overcome the problems of diffusional limitations on microporous adsorbents.

Methods: The adsorption of mesosulfuron-methyl (MM) from aqueous solution is curried out using treated acid HY zeolite.

Enhancing removal efficiency of anionic dye (Cibacron blue) using waste potato peels powder.

In the present study, the potato peel waste (PP) was used for the removal of the anionic dye Cibacron Blue P3R from an aqueous solution, activated with phosphoric acid (PPa) and calcined at 800 °C (PPc). The materials were characterized by Scanning Electron Microscope, Energy dispersive X-ray analysis and Fourier Transform Infrared Spectroscopy. The effects of various experimental parameters (pH, dye concentration, contact time) were also studied.

Effect of Brønsted acidity of HY zeolites in adsorption of methylene blue and comparative study with bentonite.

In the present study, HY zeolite with various Si/Al ratios have been used as adsorbents for the removal of a cationic dye; methylene blue, from aqueous solution using a batch process, and a comparative study with bentonite was conducted. Characterizations of the adsorbents were carried out by nitrogen adsorption-desorption, pyridine chemisorption followed by infrared spectroscopy and X-ray fluorescence. The effects of various parameters such as contact time, initial MB concentration, adsorbent concentration and solution pH were investigated.

Tuning the hydrophobicity of mesoporous silica materials for the adsorption of organic pollutant in aqueous solution.

The ability of various as-prepared and organically modified MCM-41 and HMS mesoporous silica materials to behave as efficient adsorbents for organic pollutants in aqueous solution was investigated by using different surface functionalization procedures, so as to adjust their hydrophilic/hydrophobic balance. The hydrophilic and organophilic properties of the parent silica materials and their corresponding surface functionalized counterparts were studied by using water and toluene adsorption isotherms. Their quantification was determined by the hydrophobic static index value (HI(static)), as well as by the silanol and organic group densities after the functionalization step.

Separation of monobranched and dibranched Isomers of n-hexane on zeolitic molecular sieves: a thermodynamic study.

A thermodynamic study was realized by competitive adsorption over zeolitic adsorbents to determine the efficiency of these solids for the separation of monobranched and dibranched isomers of n-hexane. The effect of the zeolite structure was studied. The medium-pores ZSM-5-type zeolites were better than the large-pores BEA and MOR zeolites.

A seven-gene, multilocus, genus-wide approach to the phylogeny of mycobacteria using supertrees.

This is the first study that estimates mycobacterial phylogeny using the maximum-likelihood method (PhyML-aLRT) on a seven-gene concatenate (hsp65, rpoB, 16S rRNA, smpB, sodA, tmRNA and tuf) and the super distance matrix (SDM) supertree method. Two sets of sequences were studied: a complete seven gene sequence set (set R, type strains of 87 species) and an incomplete set (set W, 132 species) with some missing data. Congruencies were computed by using the consense program (phylip package).

Identification of Mycobacterium using the EF-Tu encoding (tuf) gene and the tmRNA encoding (ssrA) gene.

The partial nucleotide sequences encoding the elongation factor Tu (tuf gene) (652 bp) and transfer-mRNA (tmRNA or ssrA gene) (340 bp) were determined to assess the suitability of these two genes as phylogenetic markers for the classification of mycobacteria, and thus as alternative target molecules for identifying mycobacteria. A total of 125 reference strains of the genus Mycobacterium and 74 clinical isolates were amplified by PCR and sequenced. Phylogenies of the two genes constructed by the neighbour-joining method were created and compared to a concatenated tree of 16S rDNA, hsp65, sodA and rpoB genes.

[Pet-rat bite fever and septic arthritis: molecular identification of Streptobacillus moniliformis].

Pet-rat bite fever is a relatively rare disease consecutive to a rat bite or scratch. The authors report a case of septic arthritis following a pet rat bite. Streptobacillus moniliformis was identified in the knee synovial fluid and identified by 16S rRNA sequencing.

Mycobacterium bovis infection, Lyon, France.

In a 5-year retrospective study, we used spoligotyping and mycobacterial interspersed repetitive units to type 13 strains of Mycobacterium bovis isolated from human sources. Despite the relatively high incidence of human tuberculosis caused by M. bovis (2%), these tools showed no clonal evolution and no relationships between the isolates.

16S rRNA sequencing in routine bacterial identification: a 30-month experiment.

Accurate identification of bacterial isolates is an essential task in clinical microbiology. Phenotypic methods are time-consuming and either fail to identify some bacteria such as Gram-positive rods entirely or at least fail to do so in some clinical situations. 16S rDNA sequencing is a recent method of identification which offers a useful alternative.

[Evolution of antibiotic resistance and serogroups of Streptococcus pneumoniae over the 1997-2003 period in Brittany].

At this time, many antibiotics have decreased activity against Streptococcus pneumoniae, a major agent of infectious disease. In this study, we evaluated antibiotic susceptibility and serogroups of strains isolated from bacteraemia, meningitis and acute otitis media in adults and children over the 1997-2003 period in Brittany, France. In 2003, 62% of the isolates were not susceptible to penicillin and 11% were fully resistant.

[A severely disturbed lipid profile].

We report here the case of a 30-year-old woman presenting a disturbed lipid profile since her childhood. The rarity of this pathology (Anderson' disease or chylomicron retention disease) and its recent recognition explain its late detection in this case. The description of the biochemical profile is interesting especially the low level of vitamin A and E which explains the severity of the disease.