270 research outputs found
Thioredoxin Is a New Target for the Phytotoxicity of Small Lactone Mycotoxins, Patulin and Penicillic Acid on Maize Seedlings
The phytotoxic mechanisms of patulin (PAT) and penicillic acid (PA) have not been identified unambiguously. This study aims to clarify their effects on thioredoxins (Trxs). Aflatoxin B1 (AFB1), PAT and PA were isolated by solvent extraction and chromatographic techniques from the cultures of Aspergillus flavus Z2 (LC171449), Penicillium vulpinum CM1 and Aspergillus ochraceus EMCC516, respectively. The three mycotoxins showed phytotoxicity to the germination of maize seeds, which was manifested by inhibiting radicle and coleoptile emergence, in addition to their toxic effects on fresh weights and root and shoot lengths. The phytotoxicity of AFB1 and PAT was greater than that of PA. Due to the central roles exhibited by plant Trxs in cellular metabolic activities, they were tested as target proteins for PAT and PA using AFB1 as positive control. In vivo studies showed that the mycotoxins significantly reduced Trx activity measured in the roots and shoots of maize seedlings. PAT showed greater Trx-inhibiting activity than PA and AFB1. In vitro studies of the mycotoxins on Trx y1 (from Arabidopsis thaliana) and thioredoxin reductase (Tr, from rat liver) activities confirm the results of in vivo studies. The inactivation of Trx with PAT and PA was reduced in the presence of glutathione (GSH). Data obtained suggest that lactone mycotoxins are more highly reactive with simple low-molecular-weight thiols (like GSH) than with complex ones (like Trx)
Establishment of background water quality conditions in the Great Zab River catchment:influence of geogenic and anthropogenic controls on developing a baseline for water assessment and resource management
The Great Zab River catchment is a major left-bank tributary of the River Tigris and drains a substantial part of the Kurdistan Region, an autonomous region of Northern Iraq. Within Kurdistan, the water resources of the Great Zab River catchment are under pressure from population increase and are utilized for potable, domestic and agricultural and industrial supply. As with many parts of the world, effective management of water resources within Kurdistan is hindered by a lack of water quality data and established background concentrations. This study therefore represents the first regional survey of river water chemistry for the Great Zab River catchment and presents data on the spatial and temporal trends in concentrations of As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, Li, Mn, Mo, Ni, Pb, Sr, Zn, NO3?, SO42?, F?, Cl? and PO43?, in addition to pH, electrical conductivity, dissolved oxygen and turbidity. As a tool for underpinning the management and monitoring of water quality, background concentrations were defined for the Great Zab catchment using three methods. The influences of geogenic and anthropogenic controls upon spatial and temporal trends in water chemistry are also evaluated. The influence of geogenic loading from underlying bedrock was identifiable within the observed spatial trends, with the most notable differences found between waters sampled from the relatively more volcanic-rich Zagros zone to the north and those sampled from the lower catchment underlain by younger clay-, sand- and siltstones. The greatest anthropogenic influence, identifiable through elements such as Cl? and NO3?, is present in the more highly populated lower catchment. The background concentrations identified in the Great Zab catchment would be those expected as a result of geogenic loading with some anthropogenic influence and represent a more conservative value when compared to those such as the World Health Organization Maximum Admissible Concentration. However, background concentrations represent a powerful tool for identifying potential anthropogenic impacts on water quality and informing management of such occurrencespublishersversionPeer reviewe
Cement Kiln Dust Chemical Stabilization of Expansive Soil Exposed at El-Kawther Quarter, Sohag Region, Egypt
ABSTRACT This work dealt with a chemical stabilization of an expansive high plastic soil of Pliocene deposits exposed at El-Kawther quarter using cement kiln dust (CKD) and cement kiln dust with lime (L) to reduce their swelling and improve their geotechnical properties. Several specimens of the studied expansive soil were collected from El-Kawther quarter. Chemical analysis of the used cement kiln dust and the lime was conducted. Microstructural changes were examined using scanning electron microscope (SEM) before and after chemical treatment of the studied soil. Geotechnical properties including plasticity, compaction parameters, unconfined compressive strength (qu), ultrasonic velocities and free swelling of the studied soil were measured before and after the treatment. An optimum content of the cement kiln dust was 16% (CKD). The optimum content of the cement kiln dust with the lime was 14% (CKD) with 3% (L) according to pH-test. The results showed that the addition of cement kiln dust and cement kiln dust with lime led to a decrease in maximum dry density and an increase in optimum water content. Unconfined compressive strength values were increased using cement kiln dust and cement kiln dust with lime at 7 days curing time. Ultrasonic longitudinal (Vp) and shear (Vs) velocities values were also increased by addition of the cement kiln dust and the cement kiln dust with lime at 7 days curing time. Increment of the curing time from 7 to 28 days led to an increase in both unconfined compressive strength and ultrasonic velocities values. Free swelling percent of the studied soil was reduced from 80.0% to 0.0% after the treatment
Effect of selenium on nutritive value of purslane (Portulaca oleracea L.)
Purslane (Portulaca oleracea) one of the auxiliary plants was traditionally consumed in many parts of the world for its nutritional and medicinal benefits. The nutrient components of purslane such as total protein, total carbohydrates and mineral content such as macro elements (Na, K, Ca and Mg) and micro elements (Fe, Cu, Pb and Zn) were estimated at different concentrations of selenium which treated in soil where the plant cultivated. The protein and carbohydrate contents of leaves as well as protein of stems increase with increasing the selenium concentration, while protein and carbohydrate of roots as well as carbohydrate of stems decrease with increasing Se concentration. The mineral content was also affected by Se concentration, Fe, Cu and Zn of leaves decreased with increasing Se concentration, while K, Ca, Mg and Na are directly proportional with Se concentration. In stems, Zn only is inversely proportional with Se concentration. In roots, Fe, Cu, Mg and K are inversely proportional with Se concentration, while Na, Ca and Zn are directly proportional. The findings of this study revealed that carbohydrates, protein and mineral contents of purslane can be affected and controlled by selenium concentration.
DOI: http://dx.doi.org/10.5281/zenodo.128341
RAPID AND VALIDATED HPLC-UV METHOD FOR DETERMINATION OF GEMIFLOXACIN IN HUMAN URINE
Objective: To develop and validate a simple and rapid reversed phase high performance liquid chromatographic (RP-HPLC) method for the determination of Gemifloxacin (GFX) in human urine.Methods: GFX was isolated from urine samples after acidification using methylene chloride. Good chromatographic separation was achieved using C18 Ultrasphere (250 mm × 4.6 mm, 5 µm.) analytical column maintained at 25 °C. The mobile phase consisted of methanol and 0.1 M phosphate buffer pH 3 in the ratio of (48: 52, v/v), respectively. The analysis time was 10 min at a 1.0 ml/min flow rate. The UV detection was carried out at 272 nm.Results: GFX has been eluted at 7.5 min. Linearity was obtained over a concentration range of 20-200 ng/ml (r2>0.999). The extraction recovery of GFX from urine samples was 60%. The proposed method demonstrated excellent intra-and inter-day precision and accuracy within 1.19% and 100.65 %, respectively. The limit of detection (LOD) was found to be 6.3 ng/ml.Conclusion: Simple and accurate RP-HPLC method for determination of GFX in human urine was developed and validated. The method was successfully applied for determination of GFX in human urine samples from healthy volunteers up to 24 hours after oral administration of 320 mg gemi floxacin tablets.Â
A simulation-based study to calculate all the possible trajectories of differential drive mobile robot
Deferential Drive Mobile Robot (DDMR) is being used in many applications as it is easy to be modeled and controlled. This research presents the idea of using DDMR turning motion behavior to develop an algorithm that calculate all the circular trajectories. This can be used to navigate DDMR in a curvature paths instead of linear ones. In this research we design and simulate Differential Drive Mobile Robot (DDMR) model. Then we use the simulated model to calculate all the possible trajectories that DDMR can follow with each left and right wheel velocity configurations. Results are saved in a navigation look-up table that can be implemented in DDMR navigation's approach. © 2021 Author(s)
Rotating range sensor approached for mobile robot obstacle detection and collision avoidance applications
Range finder sensors are widely used in the obstacle detection and collision avoidance applications. In this research, we propose rotating range finder sensor that provides economic and efficient solution for mobile robot applications. Rotating approach is achieved by coupling the range sensors with servomotor. In this article, rotating approach model design, main parameters, equations and limitation are described. In addition, an algorithm is developed to control the rotation angle of the range sensor, extract data from the approach and analyze it. A case study of the rotating approach by implementing ultrasonic sensor is simulated and the results are obtained. Simulation platform Gazebo and ROS are used to simulate the rotating approach. © 2021 Author(s)
Markers of neural degeneration and regeneration in Down syndrome patients
On the trisomy Down syndrome Critical Region (DSCR1) is located the APP gene, which accelerates amyloid peptide protein (APP) expression leading to cerebral accumulation of APP-derived amyloid-beta peptides (Ab) and age-dependent cognitive sequelae. Also DSCR1 attenuates endothelial cell proliferation and angiogenesis required for tissue repair. The aim of the present work is to determine markers of neural degeneration and regeneration in the blood of young and adolescent Down syndrome (DS) patients as well as controls. Markers of regeneration were measured in terms of circulating mononuclear cells expressing Nestin and CD34, while markers of degeneration were measured in terms of plasma Ab42 and advanced glycation end products receptors (RAGES). Results showed a significant increase in plasma Ab42 (20 ± 5.1 vs. 11.9 ± 3.4) and RAGES leucocytes mRNA relative expression (1.9 ±0.2 vs. 1.1 ±0.6) in adolescentDS patients compared to young DS. Both parameters were also significantly increased in DS compared to controls: Ab42 (15.4 ± 5.9 vs. 12. 3± 4.5); RAGES (1.4 ± 0.5 vs. 0.7± 0.2). Nestin (5.2 ± 1.4 vs. 6.3± 0.6) and CD34 (52 ± 2.5 vs. 53± 4.7) were non-significantly lower in adolescent DS patients compared to young DS, but significantly lower in DS patients compared to controls: Nestin (6.3 ± 1.5 vs. 9±4.4); CD34 (54 ± 3.4 vs. 60± 4.8). The significant decrease in the number of mononuclear cells bearing Nestin and CD34 markers accompanied by a significantincrease in Ab42 and RAGES indicate that degeneration in DS is an ongoing process, which is not counterbalanced by the regenerative mechanism
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