Nitrate contents in some vegetables in Tunisia

This study reports the nitrate level of 22 vegetables species collected from 40 farms in several locations of an intensive agricultural area in two regions of Tunisia (Sousse and Monastir). Nitrate levels ranged between 57 and 2970 mg kg^?1. The highest and the lowest levels were found in turnip and tomato, respectively. Only five species (potato, field bean, cauliflower, pea and artichoke) had exceeded the norms established by the World Health Organization. Factors influencing nitrate accumulation in some vegetables were analyzed and discussed. It was observed that nitrate contents in vegetables varied depending on the type of vegetables, genetic factor, level of nitrogen fertilization and soil nitrogen content.     

Potential of Exopolysaccharide from Porphyridium marinum to Contend with Bacterial Proliferation,Biofilm Formation,and Breast Cancer

Exopolysaccharide (EPS) from marine microalgae are promising sources of a new generation of drugs. However, lot of them remain to be discovered and tested. In this study, EPS produced by Porphyridium marinum and its oligomers prepared by High Pressure Homogenizer have been tested for different biological activities, i.e., antibacterial, anti-fungal and antibiofilm activities on Candida albicans, as well as for their effects on the viability of murine breast cancer cells. Results have shown that all EPS samples present some biological activity. For antibacterial and antibiofilm activities, the native EPS exhibited a better efficiency with Minimum Inhibitory Concentration (MIC) from 62.5 µg/mL to 1000 µg/mL depending on the bacterial strain. For Candida albicans, the biofilm formation was reduced by about 90% by using only a 31.3 µg/mL concentration. Concerning breast cancer cells, lower molar masses fractions appeared to be more efficient, with a reduction of viability of up to 55%. Finally, analyses of polymers composition and viscosity measurements were conducted on all samples, in order to propose hypotheses involving the activities caused by the intrinsic properties of polymers.     

Effect of genotype and growing season on nitrate accumulation and expression patterns of nitrate transporter genes in potato (Solanum tuberosum L.)

Nitrate (NO₃^?) is the most important source of mineral nitrogen (N) affecting the vegetative growth, the tuber yield and the quality of potato (Solanum tuberosum L.). The screening of 16 potato cultivars for low nitrate content was reported and the effects of genotype and experimental factors on nitrate accumulation were studied. Both genotype and growing season had a highly significant effect on dry weight, number of tubers/plant, yield and nitrate accumulation in potato which varied significantly from one genotype to another. Furthermore, nitrate accumulation varies with the season, being higher in the first season (autumn) than in the second season (spring), for all the genotypes. The cultivars Safrane and Universa followed by Actrice and Alaska produced the highest tuber yield/plant during the first and second season, respectively, accumulating higher quantities of nitrate compared to other cultivars. Ponomera cultivar was of interest from a breeding perspective due to both combining best tuber yield/plant and low nitrate accumulation for both growing season. Expression pattern of nitrate transporter genes (StNRT1.2, StNRT1.5 and StNRT2.1) has been reported. Thus, these genes were differentially expressed which could be explained in part by the difference in nitrate accumulation rate between the studied cultivars. The results showed that high accumulator genotype got significant higher expression level of StNRT1.2, StNRT1.5 or StNRT2.1 which lead to the higher nitrate uptake rate and consequently higher nitrate accumulation than low accumulator genotype.     

Molecular Networking Leveraging the Secondary Metabolomes Space of Halophila stipulaceae (Forsk.) Aschers. and Thalassia hemprichii (Ehrenb. ex Solms) Asch. in Tandem with Their Chemosystematics and Antidiabetic Potentials

The Red Sea is one of the most biodiverse aquatic ecosystems. Notably, seagrasses possess a crucial ecological significance. Among them are the two taxa Halophila stipulacea (Forsk.) Aschers., and Thalassia hemprichii (Ehrenb. ex Solms) Asch., which were formally ranked together with the genus Enhalus in three separate families. Nevertheless, they have been recently classified as three subfamilies within Hydrocharitaceae. The interest of this study is to explore their metabolic profiles through ultra-high-performance liquid chromatography-high-resolution mass spectrometry (UPLC-HRMS/MS) analysis in synergism with molecular networking and to assess their chemosystematics relationship. A total of 144 metabolites were annotated, encompassing phenolic acids, flavonoids, terpenoids, and lipids. Furthermore, three new phenolic acids; methoxy benzoic acid-O-sulphate (16), O-caffeoyl-O-hydroxyl dimethoxy benzoyl tartaric acid (26), dimethoxy benzoic acid-O-sulphate (30), a new flavanone glycoside; hexahydroxy-monomethoxy flavanone-O-glucoside (28), and a new steviol glycoside; rebaudioside-O-acetate (96) were tentatively described. Additionally, the evaluation of the antidiabetic potential of both taxa displayed an inherited higher activity of H. stipulaceae in alleviating the oxidative stress and dyslipidemia associated with diabetes. Hence, the current research significantly suggested Halophila, Thalassia, and Enhalus categorization in three different taxonomic ranks based on their intergeneric and interspecific relationship among them and supported the consideration of seagrasses in natural antidiabetic studies.     

Randomized double blind comparison between sciatic-femoral nerve block and propofol-remifentanil, propofol-alfentanil general anesthetics in out-patient knee arthroscopy

The aim of this study is the evaluation preparation and discharge times as well as the side-effects, patient satisfaction and costs after out-patient knee arthroscopy performed with a combined sciatic-femoral nerve block or a propofol-remifentanil, propofol-alfentanil general anesthetics. Sixty patients, (remifentanil group 1, n = 20), (alfentanil group 2, n = 20) and a combined sciatic-femoral nerve block (PNB group 3, n = 20). In group 1, anesthesia was induced with remifentanil (1 mic kg(-1) followed by 0.5 mic kg(-1) min(-1) i.v), in group 2 alfentanil (20 mic kg(-1) followed by 2 mic kg(-1) min(-1) i.v, in both groups (group 1, 2) propofol was given 2 mg kg(-1) i.v followed by 9 mg kg(-1) h(-1) i.v. Patients then received atracurium 0.6 mg kg(-1) i.v. to facilitate endotracheal intubation. In the PNB group (group 3), patients received a sciatic-femoral nerve block with ropivacaine 25 mL 0.75 mg using a multiple injection technique aided by a nerve stimulator and a short, bevelled, Teflon-coated stimulating needle. There was no significant difference in the duration of stay in the post anesthesia care unit and day surgery unit between groups, there was significant increase in the time to first urination in PNB group than the other two groups. Also there was no significant difference in the stay in delay surgery. The cost of disposal materials, preoperative and post operative times were higher in PNB group. The cost of drugs was higher in remifentanil and alfentanil groups than PNB group; the total cost was insignificant in the three groups. In conclusion, this prospective randomized study suggests that in patients undergoing out-patient arthroscopy, a combined sciatic-femoral nerve block (using a small volume of ropivacaine 0.75%) compared with a propofol-remifentanil or propofol-alfentanil general anesthetics techniques may provide similar intraoperative analgesic efficacy, a shorter length of stay in the PACU and an increased likelihood of bypassing the first phase of postoperative recovery.     

A mixed methods study of ruminant brucellosis in central-eastern Tunisia

In this study, we conducted an investigation to determine the true prevalence of bovine and ovine brucellosis in central-eastern Tunisia. A total of 1134 veterinary samples taken from 130 ruminant herds were screened for brucellosis using IS711-based real-time PCR assay. Sera collected from the ruminants were tested using the Rose Bengal test and indirect enzyme-linked immunosorbent assay. Based on serological and molecular results, the true adjusted animal population level prevalence was 23.5 % in cattle, against 13.5 % in sheep. In addition, the true adjusted herd level prevalence of brucellosis was 55.6 % in cattle and 21.8 % in sheep. A statistically significant association was found between vaginal and milk shedding for ruminants. In addition, our results showed that Brucella abortus could be responsible for bovine and ovine brucellosis. Multivariable logistic regression analysis at the animal population level indicated that age and origin variables were important risk factors for cattle. However, age and abortion variables were found to be associated with ovine brucellosis. At the herd level, risk factors for Brucella positivity were as follows: abortion and herd composition for cattle against herd composition, mortality rates, and hygiene for sheep. Animal hygiene, food quality, and sanitary practices on the farm should be applied as strategies to control brucellosis in herds.     

Physico-chemical characteristics of a seed fiber arised from <Emphasis Type="Italic">Pergularia Tomentosa</Emphasis> L.

In the present paper, we analyze a seed fiber arising from Pergularia tomentosa L. (PTL). It was, primarily, characterized using different techniques. The morphology of the fibers was observed via Scanning Electron Microscopy (SEM). They are also checked in term of decomposition behavior through TGA/DTG instrument. The cristallinity index was determined using XRD and it was about 52 %. The chemical composition in terms of moisture percent, ash, waxes and fats, lignin, hemicellulose and cellulose were, respectively 8.5 %, 2.74 %, 1.88 %, 8.6 %, 16 % and 43.8 %. The contact angle value was measured and the evolution of drop profile was captured with video-camera using GBX Tensiometer Surfaces Sciences Studies. Further, fibers were dyed with Methylene Blue, Direct Red 79, Sumifix supra yellow 3RF and Reactive Blue 198. Color coordinates (ΔL*, Δa*, Δb*, ΔC* and ΔH*) of the samples were so measured. All obtained data were compared to cotton fibers and some other cellulosic fibers. The Results revealed that, based on such properties, PTLF could be a competitive fiber in many applications field (textile weaving, composites, etc).