Assessment of environmental hazards in the north western coast -Egypt using RS and GIS

AbstractSoil erosion, salinity and sodicity hazards are serious problems in the northern west coast of Egypt and lead to reducing the soil quality and increasing the degradation of soil resources. Sidi Barrani and Al-Sallum regions are selected as study areas which are located from a longitude of 25°10′00″ to 26°55′00″East and from a latitude of 31°00′0″ to 31°37′30″ North. Erosion hazard was estimated using the ‘Universal Soil Loss Equation’ (USLE), which is a simple empirical model that is widely used for assessing long-term annual soil loss .The salinity and sodicity hazards were estimated based on FAO method as standard reference. The resultant map of annual soil erosion shows a maximum soil loss of 60th−1y−1with a close relation to foot slopes and wide units on the steep side-slopes (with high LS value) and the erodibility value reached to 0.1th−1y−1. Meanwhile sand beaches and sabkha units are characterized by high environmental hazards of both water erosion, salinity and sodicity, while in the overflow basin units are identified as low environmental hazards. The spatial environmental hazards assessment is conducted by using integrated GIS and RS which can serve as effective inputs in deriving strategies for sustainable land use planning and management

HPLC-DAD stability indicating determination of nizatidine in bulk and capsules dosage form

AbstractThis work describes the stability-indicating determination of the H2-receptor antagonist nizatidine in its bulk and capsules dosage form using high performance liquid chromatography coupled with diode array detector (HPLC-DAD). The developed method involved the use of Thermo Hypersil BDS-C8 (4.6×250mm, 5μm particle size) column and a mobile phase composed of 0.05M phosphoric acid and acetonitrile (50:50, v/v). The mobile phase was pumped at a flow rate of 1mL/min. Quantification of nizatidine was based on measuring its peak area at 320nm. The retention time for nizatidine was about 3.61min. The reliability and analytical performance of the proposed HPLC procedure were statistically validated with respect to linearity, range, precision, accuracy, specificity, robustness, detection and quantification limits. Calibration curve of nizatidine was linear in the range of 5–50μg/mL with correlation coefficient >0.9999. The drug was subjected to forced-degradation conditions of acidic and basic hydrolysis, oxidation, dry heat and UV photolysis where it showed considerable degradation in basic and oxidative conditions. The proposed method proved to be specific and stability-indicating by resolution of the drug from its forced-degradation products. The validated HPLC method was applied to the analysis of nizatidine in capsules dosage form where it was quantified with recoveries not less than 98.2%. Assay results were statistically compared to USP 2011 pharmacopeial method where no significant difference was observed between the proposed and reference methods

Composition and Distribution of Aquatic Weeds in some Minor Canals, Gezira Scheme, Sudan (2018)

Excessive growth of aquatic weeds in irrigation systems is a worldwide problem. In Sudan, many irrigation schemes have been greatly affected by aquatic weeds such as Gezira scheme. The objective of the study was to evaluate the community composition and distribution of aquatic weeds in some minor canals in the Gezira scheme in 2018. The study area covered six minor canals at Centre Group at Gezira Scheme. Each minor canal was divided into three sections%253B head, middle and tail (18 sampling sites). The sites were surveyed once in every month for a period of three months during summer and winter seasons. The community composition of aquatic weeds was detected by visual observation, whereas the distribution of aquatic weeds was determined by calculation of percentage of relative frequency. Data were subjected to descriptive analysis and to analysis of variance. The results indicated that the community composition in the six minor canals consists of four groups of aquatic weeds as follows%253B floating, emergent, submergent and bank aquatic weeds and consisted of 12 species belonging to nine families. Results showed considerable differences in distribution throughout the year. The most dominant species within the groups were%253B Vossia cuspidata (33%25 - 41%25) within the group of floating weeds, Cyperus alopecuroides (87%25 - 55%25) within the group of emergent weeds and Cynodon dactylon (75%25 - 83%25) within the group of bank aquatic weeds during both summer and winter seasons. Submergent weeds present only in winter season in one species Najas pectinata. Also, results of relative frequency within all aquatic species showed that Vossia cuspidata and Cynodon dactylon were the most dominant species. These finding gives many insights about the problems of aquatic weeds in minor canals and would be useful in the management and control of aquatic weeds

Influence of blend ratio on the electrical characteristics of vulcanized SBR/NBR blends compatibilized by Cis-polybutadiene rubber

Blends composed of styrene butadiene rubber (SBR) and acrylonitrile-butadiene rubber (NBR) have been fabricated by melt-blending technique using two-roll mill blend machine. Cis-polybutadiene rubber (CBR) was used as a compatibilizer for enhancing the homogeneity between blend phases. No previous reports were found to discuss improving electrical properties of vulcanized SBR/NBR blends using unfilled rubber system (i.e. no fillers incorporation). SEM micrographs were utilized to verify the compatibility between two rubber ingredients in various blends, owing to the use of compatibilizer. Thermal stability of blends was investigated by differential thermal analysis (DTA) and differential scanning calorimetric (DSC) to evaluate the influence of blend ratio on the compatibility of investigated samples. Results revealed that the dielectric properties of blends are dramatically influenced by altering the blend ratio. The results revealed that the SEM observations confirmed the compatibilization effect of CBR on vulcanized SBR/NBR blends. Meanwhile, thermal properties of vulcanized SBR/NBR blends were enhanced with increasing of SBR contents in blends. The complex impedance graphs showed circular arcs showing the bulk contribution to overall electrical behavior for investigated vulcanized SBR/NBR blends. During I-V characteristics have been presented, where a remarkably change from linear behavior to nonlinear conduction at lower temperatures was found for 0SBR/100NBR blends. These findings supported and confirmed that the compatibilization effect and the blend ratio between rubber compositions have strongly influenced on their thermal and electrical properties of vulcanized blends

Monitoring and bioremediation of organochlorine pesticides in surface water with Enterobacter asburiae

Aim of study: One of the safest techniques regarding the remediation of contaminated water is biological remediation. This study aimed to: (i) monitoring of a collection of organochlorine pesticides (OCPs) in three agricultural drainages (Nashart, no. 9, and El-shoka), located in Kafr El-Sheikh governorate, Egypt; and ii) investigate the biodegradation potential of different bacterial isolates regarding organochlorine pesticides.Material and methods: Analysis of OCPs was carried out by gas chromatography, Enrichment cultures were used for isolation of the bacterial strains capable of OCPs biodegradation and the most efficient isolate was identified based on morphological, biochemical ad molecular characteristics.Main results: The determination of OCPs in water samples by gas chromatography showed varying values of OCPs ranging from 0.0 mg/L (below detection limit) to 0.0385 mg/L. A total of four morphologically different bacterial isolates were obtained, which showed a remarkable capability of OCPs biodegradation detected in mineral salt medium containing 17 OCPs active ingredients by two approaches including the analysis of the OCP residues at the end of the incubation period and measuring the bacterial growth in terms of total viable count and optical density. The bacterial isolate N2 showed the highest degradation capability when the screening process was carried out to select the most efficient isolates, which was identified according to the morphological, biochemical and molecular characterization as Enterobacter asburiae.Research highlights: The biodegradation of OCPs using E. asburiae was proved to be a promising approach for the detoxification and removal of OCPs residues in aqueous systems

Structural and Functional Abnormalities in the Caudate Nucleus of Schizophrenic Patients with and without Obsessive Symptoms

Background: Obsessive\u2013compulsive symptoms (OCS) have been frequently described in schizophrenic populations. There is a controversy on whether this co-occurrence is more than just comorbidity or represents a distinct subgroup in schizophrenia. Aim: The aim of this study was to investigate whether there are possible underlying structural and functional differences between schizophrenic patients with and those without OCS. Patients and methods: Participants in this study were divided into three groups: 20 patients having schizophrenia with OCS; 20 patients having schizophrenia without OCS (both were diagnosed according to DSM-IV-TR); and 20 matching controls. All participants underwent an MRI for volumetric measurement of the caudate nucleus and a magnetic resonance spectroscopy to measure choline (Cho), creatine, and N-acetyl aspartate (NAA) in the caudate nucleus. Results: Caudate volume was found to be reduced in schizophrenic patients with or without OCS (P 640.05). Magnetic resonance spectroscopy findings showed that schizophrenic patients without OCS had significant increase in Cho concentration (P 640.05), but average NAA concentration. In contrast, schizophrenic patients with OCS had significant reduction in NAA concentration (P 640.05) with average Cho concentration. Conclusion: Schizophrenic patients with OCS may have an atypical set of neuroradiological characteristics that would specifically categorize it within the schizophrenia spectrum

Broadband telecom to mid-infrared supercontinuum generation in a dispersion-engineered silicon germanium waveguide

We demonstrate broadband supercontinuum generation (SCG) in a dispersion-engineered silicon-germanium waveguide. The 3 cm long waveguide is pumped by femtosecond pulses at 2.4 μm, and the generated supercontinuum extends from 1.45 to 2.79 μm (at the −30  dB point). The broadening is mainly driven by the generation of a dispersive wave in the 1.5–1.8 μm region and soliton fission. The SCG was modeled numerically, and excellent agreement with the experimental results was obtained

Development and validation of stability indicating method for determination of sertraline following ICH guidlines and its determination in pharmaceuticals and biological fluids

<p>Abstract</p> <p>Background</p> <p>Sertraline is a well known antidepressant drug which belongs to a class called selective serotonin reuptake inhibitor. Most published methods do not enable studying the stability of this drug in different stress conditions.</p> <p>Results</p> <p>Two new methods were developed for the determination of sertraline (SER). Both methods are based on coupling with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) in borate buffer of pH 7.8 and measuring the reaction product spectrophotometrically at 395 nm (Method I) or spectrofluorimetrically at 530 nm upon excitation at 480 nm (Method II). The response-concentration plots were rectilinear over the range 2-24 μg/mL and 0.25-5 μg/mL for methods I and II respectively with LOD of 0.18 μg/mL and 0.07 μg/mL, and LOQ of 0.56 μg/mL and 0.21 μg/mL for methods I and II, respectively.</p> <p>Conclusion</p> <p>Both methods were applied to the analysis of commercial tablets and the results were in good agreement with those obtained using a reference method. The fluorimetric method was further applied to the in vivo determination of SER in human plasma. A proposal of the reaction pathway was presented. The spectrophotometric method was extended to stability study of SER. The drug was exposed to alkaline, acidic, oxidative and photolytic degradation according to ICH guidelines. Moreover, the method was utilized to investigate the kinetics of oxidative degradation of the drug. The apparent first order rate constant and t_1/2of the degradation reaction were determined.</p

Validated spectrophotometric methods for determination of Alendronate sodium in tablets through nucleophilic aromatic substitution reactions

<p>Abstract</p> <p>Background</p> <p>Alendronate (ALD) is a member of the bisphosphonate family which is used for the treatment of osteoporosis, bone metastasis, Paget's disease, hypocalcaemia associated with malignancy and other conditions that feature bone fragility. ALD is a non-chromophoric compound so its determination by conventional spectrophotometric methods is not possible. So two derivatization reactions were proposed for determination of ALD through the reaction with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) and 2,4-dinitrofluorobenzene (DNFB) as chromogenic derivatizing reagents.</p> <p>Results</p> <p>Three simple and sensitive spectrophotometric methods are described for the determination of ALD. Method I is based on the reaction of ALD with NBD-Cl. Method II involved heat-catalyzed derivatization of ALD with DNFB, while, Method III is based on micellar-catalyzed reaction of the studied drug with DNFB at room temperature. The reactions products were measured at 472, 378 and 374 nm, for methods I, II and III, respectively. Beer's law was obeyed over the concentration ranges of 1.0-20.0, 4.0-40.0 and 1.5-30.0 μg/mL with lower limits of detection of 0.09, 1.06 and 0.06 μg/mL for Methods I, II and III, respectively. The proposed methods were applied for quantitation of the studied drug in its pure form with mean percentage recoveries of 100.47 ± 1.12, 100.17 ± 1.21 and 99.23 ± 1.26 for Methods I, II and III, respectively. Moreover the proposed methods were successfully applied for determination of ALD in different tablets. Proposals of the reactions pathways have been postulated.</p> <p>Conclusion</p> <p>The proposed spectrophotometric methods provided sensitive, specific and inexpensive analytical procedures for determination of the non-chromophoric drug alendronate either per se or in its tablet dosage forms without interference from common excipients.</p> <p>Graphical abstract</p> <p><display-formula><graphic file="1752-153X-6-25-i3.gif"/></display-formula></p