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11.
A A Wahbi M A Abounassif E R Gad-Kariem M E Ibrahim H Y Aboul-Enein 《Journal of the Association of Official Analytical Chemists》1988,71(1):31-33
A rapid, sensitive and precise liquid chromatographic method is presented for the determination of aztreonam alone, in the presence of its degradation product, and in a parenteral formulation containing l-arginine. A reverse phase column and 0.2M phosphate buffer (pH 6)-methanol (95 + 5) with mobile phase at a flow rate of 2 mL/min is used. The method is sensitive for the range of 10-50 micrograms/mL with a relative standard deviation of less than 2%. The method has been applied to a parenteral formulation containing aztreonam and l-arginine. L-Arginine is also determined by a nonaqueous titrimetric method. 相似文献
12.
A rapid method is presented for determining strychnine and brucine in liquid galenicals. At pH 5.0, both strychnine and brucine are complexed with methyl orange. After treatment with 0.1N NaOH, the liberated alkaloids are determined spectrophotometrically, using the 2-wavelength method of analysis. The method has been successfully applied to the analysis of 4 batches of nux vomica tincture, nux vomica acid, and nux vomica alkaline mixtures. The method has a relative standard deviation of 0.52%. 相似文献
13.
H. Mhadhbi V. Fotopoulos N. Djebali A. N. Polidoros & M. E. Aouani 《Journal of Agronomy and Crop Science》2009,195(3):225-231
Three genotypes of the model legume Medicago truncatula were assessed for symbiotic effectiveness in cross inoculation with two strains of Sinorhizobium meliloti under mannitol-mediated osmotic stress. Symbioses showed different tolerance levels revealed on plant growth, nitrogen-fixing capacity and indices of nodule functioning and protection. The variability of stress response was essentially correlated with performance at non-stressful conditions. Symbiosis attitude depended on bacterial partner, host-plant genotype and their interaction. Plant genotype manifested the highest contribution to symbiotic efficiency indices under osmotic stress, even for nodulation and nitrogen fixation where the bacterial strain effect is highly pronounced. Contrasting (tolerant/sensitive) associations were identified for tolerance behaviours, involving the same plant genotype with different rhizobial strains and vice versa. In nodules, osmotic stress leads to accumulation of oxidized lipids and decrease in total protein and leghaemoglobin contents. Antioxidant responses were manifested as induction of guaiacol peroxidase (POX, E.C. 1.11.1.7) and superoxide dismutase (E.C. 1.15.1.1). POX induction was higher in tolerant symbioses and both enzymes were suggested as contributors to the protection of nodule integrity and functioning under osmotic stress. In conclusion, symbiotic efficiency in M. truncatula–S. meliloti combinations under osmotic stress is determined by each symbiont's input as well as the plant–microbe genotype interaction, and POX induction could prove a sensitive marker of tolerant symbioses. 相似文献
14.
Zouhaier Barhoumi Abdallah Atia Mokded Rabhi Wahbi Djebali Chedly Abdelly Abderrazak Smaoui 《植物养料与土壤学杂志》2010,173(1):149-157
Salinity and low nitrogen availability are important growth‐limiting factors for most plants. Our objective was to assess the influence of nitrogen (N) and salt levels on the growth and mineral nutrition of three forage grasses of varying salt resistance which are widely found in Tunisian salt lands, Aeluropus littoralis, Catapodium rigidum, and Brachypodium distachyum. Their response to salt and N interaction has not been studied and further investigations are necessary. Twenty day–old plantlets were hydroponically cultivated in Hewitt's nutrient solution. Half the plants were then exposed to 100 mM NaCl and the other half to no NaCl, and N was supplied at 0.5 or 5.0 mM N as NH4NO3. Plants were harvested after 60 d growth. Saline treatment (100 mM NaCl) decreased growth of B. distachyum (a relatively salt‐sensitive plant), but no significant effect was noted for A. littoralis (a relatively salt‐resistant plant) in both low– and high–N availability treatments. However, the effect of 100 mM NaCl on growth of C. rigidum (a moderately salt‐resistant plant) depended on N level. Increasing N availability and NaCl did not influence phosphate, sulfate, calcium, and magnesium concentrations in both A. littoralis and C. rigidum, but increased N supply reduced shoot sodium and chloride (Cl–) accumulation. Potassium acquisition in A. littoralis and C. rigidum plants was severely depressed by increasing N availability under saline and nonsaline conditions, respectively. In these species, the increase of nitrate accumulation via N was attenuated by salinity. In contrast, total N content and allocation toward shoots were enhanced in these conditions, especially in A. littoralis, the most resistant species. It appears that increasing N availability at moderate salt levels has a beneficial effect on growth of species with high and moderate salt resistance, but not on species with low resistance to salinity. 相似文献
15.
Lamaoui Mouna Chakhchar Abdelghani EL Kharrassi Youssef Wahbi Said El Modafar Cherkaoui 《Journal of Crop Science and Biotechnology》2018,21(4):407-416
Journal of Crop Science and Biotechnology - In this study, the impact of two water-saving techniques, Regulated Deficit Irrigation (RDI) and Partial Rootzone Drying (PRD) was investigated by... 相似文献
16.
Sadoth Sandoval-Torres Wahbi Jomaa Fran?oise Marc Jean-Rodolphe Puiggali 《Wood Science and Technology》2012,46(1-3):177-191
The formation of chromophore groups from a phenolic compound oxidized with air and the formation of dark materials from hydrolysable extractives are considered as causes of discoloration. In this work, the colour changes, antioxidant capacity, and Fourier Transform Infrared Spectra of dust-wood are investigated in European oak wood under different plain vacuum drying conditions. The conductive heat source is maintained at four temperatures (46, 61, 70 and 80°C), and vacuum in the chamber is controlled at three different intervals (60–100, 150–200, and 250–300?mbar). Drying kinetics and temperature profiles are presented. The results suggest that degradation of extractives allows yellowing in wood and temperature improves lightness under these special drying conditions (plain vacuum). Furthermore, the presence of carbonyl groups in surfaces is related to the loss in antioxidant potency. 相似文献
17.
A 20-week growth trial was conducted to investigate the effect of two dietary blended vegetable oils (VO) on liver lipogenic
enzyme activity, liver and gonad lipid class composition and fatty acid profiles, serum sex hormones, and gonad morphohistology
in gilthead seabream, Sparus aurata. Three groups of fish (BW
i
130.9 ± 3.1 g) were fed, close to satiation, three experimental diets: a control (CTRL) contained fish oil (FO) as the sole
lipid source (100% FO) and two VO-blended diets in each 60% of FO was substituted by an equal mixture of cottonseed oil (CO),
sunflower oil (SFO) and either linseed oil (LO) or soybean oil (SBO), designated as LO or SBO diet, respectively. Each diet
was assigned to triplicate groups of fish. Results showed that all dietary treatments presented no significant (P > 0.05) differences in growth rate and feed conversion ratio for sexes combined. Enzyme activities of liver lipogenic enzymes
of LO-fed fish (glucose-6-phosphate dehydrogenase (G6PDH), malic enzyme (ME) and fatty acid synthetase (FAS)) were not statistically
(P > 0.05) different from those of CTRL fish. Only in the group of fish fed the SBO diet, G6PDH was slightly higher (P < 0.05) for both sexes, while ME showed a significant (P < 0.05) higher activity only in females relative to CTRL fish. Liver FAS enzyme activity remained unaltered among dietary
groups. VO-fed fish recorded a significant (P < 0.05) increase in total lipid (TL) and triglyceride (TAG) contents in both liver and gonad, more pronounced in females
than in males, concurrent with a significant (P < 0.05) decrease in cholesterol (CHL) and phospholipids (PL), more obvious for the SBO-fed fish, as compared to CTRL. The
fatty acid (FA) composition of liver or gonad reflected that of the supplied diet and evidenced a significant (P < 0.01 or <0.05) alteration in the majority of individual FA in VO-fed fish compared to CTRL. There were decreased levels
of ARA (20:4 n-6), EPA (20:5 n-3), and DHA (22:6 n-3) in VO-fed fish, more pronounced in females than in males, compared to
CTRL. The liver and gonad FA profiles, for males and females, reflected the composition of the diet and showed sex variation
in the output of multivariate principal component analysis (PCA). Feeding fish VO diets has also led to a significant (P < 0.05) reduction in serum estradiol level by 15.8 or 22.3% in LO- or SBO-fed fish, respectively, and in testosterone level
by 7.7% in the latter dietary group only compared to the CTRL. Histomorphological examination of ovary and testis has indicated
a relative retardation in oogenesis and spermatogenesis in VO-fed fish, less obvious in the LO-fed fish compared to CTRL.
These results suggest a preference of LO over SBO blend diet in terms of liver lipogenic enzyme activity, liver and gonad
lipid content, lipid class composition and fatty acid profile, serum sex hormones as well as gonad maturation. PCA analysis
of gonads highlighted the importance of using a 100% marine FO diet for gilthead seabream broodstock for the recovery of a
normal FA profile in gonads of fish, previously fed VO over the production cycle, to ensure successful spawning. 相似文献
18.
Tawfik El Moussaoui Laila Mandi Said Wahbi Salvatore Masi Naaila Ouazzani 《Archives of Agronomy and Soil Science》2013,59(13):1900-1912
ABSTRACTThe present work aims to perform an experimental reuse study of raw and sustainable treated urban wastewaters in the irrigation of alfalfa (Medicago sativa L.) under semi-controlled conditions. The obtained results highlight a significant effect (p < 0.05) of water quality on soil monitored parameters. Compared to control soils irrigated with groundwater (GW), those irrigated with treated urban wastewaters from the modified activated sludge process (PTW) and raw urban wastewater (RW) showed significant increase in their organic matter (OM) and nutrients content. Indeed, in comparison to GW organic matter (OM) of RW and PTW was 5,37 and 3,84 times higher; Kjeldahl nitrogen (TKN) was 3,50 and 2,81 times higher and total phosphorus (TP) was 4,00 and 3,25 times higher, respectively. The results showed also a significant effect of water quality on yield, macro and microelements concentrations of alfalfa plant. Hence, the highest yield, macro and microelements uptake of the plant were obtained in response to irrigation with PTW and RW compared to control soil GW. Concerning trace metallic elements concentrations, pots irrigated with RW and PTW showed relatively higher concentrations than those of GW pots. 相似文献
19.
M E Mohamed A A Wahbi E R Gad-Kariem M M Hassan 《Journal of the Association of Official Analytical Chemists》1984,67(4):684-687
Tiaprofenic acid (Surgam) has been determined directly by using differential pulse polarography (DPP) and pH 5.5 acetate buffer as a supporting electrolyte. The differential pulse polarogram was obtained under constant amplitude pulses of 50 mV superimposed on a linearly increasing dc ramp. Peak current was measured at the peak potential of -0.990 V vs Ag/AgCl reference electrode. Under the experimental conditions used, a linear relationship between peak current and concentration was established over the range 0.5-5.0 micrograms/mL. Mean percentage recoveries for tiaprofenic acid in authentic and tablet forms were 100.27 +/- 2.25 and 99.45 +/- 1.44, respectively. The results obtained by the DPP method were compared with those of the spectrophotometric method used by the manufacturer for the analysis of tiaprofenic acid and its tablet form. 相似文献
20.