University of Monastir

About: University of Monastir is a education organization based out in Monastir, Tunisia. It is known for research contribution in the topics: Adsorption & Population. The organization has 5072 authors who have published 7488 publications receiving 78620 citations. The organization is also known as: UM.

Prevention of 7-ketocholesterol-induced side effects by natural compounds.

Abstract: Cholesterol oxidation products, also named oxysterols, can be formed either by cholesterol auto-oxidation, enzymatically or both Among these oxysterols, 7-ketocholesterol (7KC) is mainly formed during radical attacks that take place on the carbon 7 of cholesterol As increased levels of 7KC have been found in the tissues, plasma and/or cerebrospinal fluid of patients with major diseases, especially age-related diseases (cardiovascular diseases, eye diseases, neurodegenerative diseases), some cancers, and chronic inflammatory diseases, it is suspected that 7KC, could contribute to their development Since 7KC, provided by the diet or endogenously formed, is not or little efficiently metabolized, except in hepatic cells, its cellular accumulation can trigger numerous side effects including oxidative stress, inflammation and cell death To counteract 7KC-induced side effects, it is necessary to characterize the metabolic pathways activated by this oxysterol to identify potential targets for cytoprotection and geroprotection Currently, several natural compounds (tocopherols, fatty acids, polyphenols, etc) or mixtures of compounds (oils) used in traditional medicine are able to inhibit the deleterious effects of 7KC The different molecules identified could be valued in different ways (functional foods, recombinant molecules, theranostic) to prevent or treat diseases associated with 7KC

Ocular manifestations of emerging infectious diseases.

Abstract: Purpose of review Emergent and resurgent infectious diseases are major causes of systemic morbidity and death that are expanding worldwide mainly because of climate changes and globalization. Among them, specific diseases have been recently associated with ocular involvement. This review presents the ocular manifestations of selected emerging infectious diseases relevant to the ophthalmologist. Recent findings An array of ocular manifestations, involving mainly the posterior segment, have been recently described in association with specific arthropod vector-borne diseases including rickettsioses, West Nile virus, Rift Valley fever, Dengue fever, and Chikungunya. Influenza A (H1N1) virus has also been recently associated with ocular involvement. On the contrary, with advances in laboratory testing applied to ocular fluids, new infectious agents, mainly viruses, are increasingly being found to be associated with uveitis. Summary Emerging infectious diseases should be considered in the differential diagnosis of retinitis, chorioretinitis, retinal vasculitis, optic neuropathy, or any other ocular inflammatory condition in a patient living in or traveling back from a specific endemic area. On the contrary, ocular fluid sampling and analysis for specific new pathogens can be recommended in selected patients with uveitis of unexplained cause.

Bacteriological and physico-chemical assessment of wastewater in different region of Tunisia: impact on human health

Abstract: In many parts of the world, health problems and diseases have often been caused by discharging untreated or inadequately treated wastewater. In this study, we aimed to control physico-chemical parameters in wastewater samples. Also, microbiological analyses were done to reveal Salmonella strains and each Escherichia coli (E.coli) pathotype. Sixty wastewater samples were collected from fifteen different regions of Tunisia. All physico-chemical parameters (pH, residual free chlorine, total suspended solids, biological oxygen demand, and chemical oxygen demand) were evaluated. For microbiological analyses, samples were filtered to concentrate bacteria. DNA was extracted by boiling and subjected to polymerase chain reaction (PCR) using different pairs of primers. The mean pH values recorded for the sampling point were above the WHO pH tolerance limit. The total suspended solids (TSS) concentrations varied between 240 mg/L and 733 mg/L in entrance points and between 13 mg/L and 76 mg/L in exit points. In entrance points, the studied wastewater has an average COD concentration that varied between 795 mg/mL to 1420 mg/mL. Whereas, BOD concentration of the wastewater ranged between 270 mg/L to 610 mg/L. In exit points, COD concentration varied between 59 mg/L and 141 mg/L, whereas BOD concentration ranged from 15 mg/L to 87 mg/L. The bacteriological control of wastewaters showed that, in entrance points, Escherichia coli (E.coli) was detected at the rate of 76.6%. Three E.coli pathotypes were found: ETEC (53.3%), EAEC (16.6%) and EIEC (6.6%). Concerning the ETEC isolated strains, 8 of 16 (50%) have only the heat-labile toxin gene, 5 of 16 (31.2%) present only the heat-stable toxin gene and 3 of 16 (18.7%) of strains possess both heat-labile toxin gene and heat-stable toxin gene. In exist point, the same pathotypes were found but all detected ETEC strains present only the "est" gene. Concerning Salmonella isolated strains; percentages of 66.6% and 20% were found in entrance and exit points respectively. Wastewaters contain a large amount of pathogenic bacteria that present a real impact on human health. Assessment wastewater treatment stations have to consider in account enterobacterial pathogens as potential pathogens that should be correctly controlled.

Theoretical investigation of the relative stability of Na⁺He(n) (n = 2-24) clusters: many-body versus delocalization effects.

Abstract: The solvation of the Na(+) ion in helium clusters has been studied theoretically using optimization methods. A many-body empirical potential was developed to account for Na(+)-He and polarization interactions, and the most stable structures of Na(+)He(n) clusters were determined using the basin-hopping method. Vibrational delocalization was accounted for using zero-point energy corrections at the harmonic or anharmonic levels, the latter being evaluated from quantum Monte Carlo simulations for spinless particles. From the static perspective, many-body effects are found to play a minor role, and the structures obtained reflect homogeneous covering up to n = 10, followed by polyicosahedral packing above this size, the cluster obtained at n = 12 appearing particularly stable. The cationic impurity binds the closest helium atoms sufficiently to negate vibrational delocalization at small sizes. However, this snowball effect is obliterated earlier than shell completion, the nuclear wavefunctions of (4)He(n)Na(+) with n = 5-7, and n > 10 already exhibiting multiple inherent structures. The decrease in the snowball size due to many-body effects is consistent with recent mass spectrometry measurements.