172 research outputs found
Design, Engineering Analysis, and Fabrication of a Prototype Electromechanical Finger Fixator Control System
This paper investigates a new external fixator system for treating finger contractures. This innovative system is electric and user-friendly, providing precise readings of the angles of diseased finger joints. Accurate measurements of the angles of the diseased finger joints can assist therapists and patients during rehabilitation procedures. The fixator consists of ten parts assembled using polyether-ether-ketone (PEEK) for the plastic components and stainless steel for the metal components. The design model was engineered, drawn, and analyzed using SolidWorks Computer-Aided Design software. The verification process utilizes finite element analysis to demonstrate that the maximum stress was lower than the yield strength of the chosen materials. As a result, the new device design is robust and stable enough to withstand the anticipated loading conditions of human fingers. Subsequently, a prototype was fabricated using advanced additive manufacturing technology, specifically fused deposition modeling (FDM). The proposed fixator is simple to control, reliable, easy to use, and reproducible. It enables device users to exercise their finger joints throughout the day without requiring the assistance of specialists
The critical level of vitamin D in childhood asthma
Objectives: Studies have suggested a significant link between vitamin D status and asthma. We sought to determine the cutoff level of25 hydroxy (25-OH) vitamin D that is significantly linked to asthma status in children.Methods: Our cross-sectional study comprised 90 asthmatic children, aged 2-18 years. They were evaluated clinically and classified according to asthma severity and control. Asthma control test (ACT) was performed in those aged above 4 years.Pulmonary functions were performed in cooperative children (n=59). Serum 25-OH vitamin D levels were measured by ELISA in all patients.Results: The study comprised 52 boys (57.7%) and 38 girls (42.3%) with mean age 7.03±4.36 years. Thirty-six patients (40%) had mild asthma, 37 (41%) moderate asthma and 17 (19%) had severe asthma. Forty-two patients (46.6%) had controlled asthma; 14 (15.6%) partially controlled and 34 (37.8%) had uncontrolled asthma. ACT score ranged: 11-26, with mean score: 18.9 ± 4.3 SD. Serum 25-OHvitamin D levels ranged between 2-48 ng/ml (mean± SD: 12.2 ± 9 ng/ml); levels were comparable among different grades of asthma severity (f= 1.975, p=0.145), while the uncontrolled asthma group showed the lowest levels (f=8.511, p <0.001). 25-OH vitamin D levels correlated positively with ACT score (r= 0.369, p= <0.001) but not with inhaled steroids doses or any of the pulmonary function parameters. A level of 7.5 ng/ml was associated with partial/completeuncontrol of asthma with 81 % sensitivity and 53 % specificity.Conclusion: 25-OH vitamin D levels below 7.5 ng/ml are associated with poor asthma status in children.Keywords: Asthma, allergy, children, severity, inhaled steroids, 25 hydroxy vitamin D
Optimization and Characterization of Extracellular Cellulase Produced by Native Egyptian Fungal Strain
Since accumulation of agricultural wastes represents a huge problem, it was important to explore the available methods to help eliminate agricultural wastes safely, and simultaneously produce functional enzyme like cellulase. Six native Egyptian fungal strains were isolated, morphologically identified and screened for cellulose biodegradation potential, which was determined as endoglucanase or as carboximethylcellulase (CMCase). The most promising isolate (Aspergillus terreus) was selected for molecular characterizations based on sequencing of internal transcribed spacer (ITS). Further optimization experiments were accomplished on the selected strain. The strain with cellulolytic activity, 2.26 IU mL-1 was identified using ITS nucleotides (genes) sequences and the result confirmed that the strain is 99.8% homology with A. terreus. Then, it was submitted to GeneBank and given an accession number. Further optimization experiments revealed that 35ºC is the optimum temperature for cellulase production and raised the enzyme activity (EA) up to 3.19 IU mL-1. Out of two organic nitrogen sources; peptone at concentration 6 gL-1 was found to be the optimum nitrogen source for cellulase production with the highest activity 4 IU mL-1. Whereas, the different four carbon sources: microcellulose, corn stalks, wheat straw and rice straw showed significant differences in EA with values 11.07, 9.68, 7.87 and 3.71 IU mL-1, respectively at pH 3. The maximum EA was recorded to be within 5-7 days of incubation, dependent on type of carbon sources. The optimization of different incubation conditions raised cellulolytic activity from 2.26 IU mL-1 up to 11.18 IU mL-1
Geochemical characterization of recent Nile Delta inner shelf sediments: Tracing natural and human-induced alterations into a deltaic system
Abstract The present study deals with the geochemical changes observed along Nile Delta inner shelf sediments over a period of 20 years (1995–2015). Major, minor, and trace constituents as well as rare earth elements (REE) were investigated in the surface sediments collected from seven transects along the inner shelf on five years intervals. Geochemical composition of sediments in Nile Delta inner shelf exhibits continuous changes over time due to the depositional and sediment transport processes. The sediments are generally enriched with Fe and Ti oxides, as well as Ta, Nb, Y in comparison to the Upper Continental Crust (UCC). These alterations signify the impact of processes such as erosion and sediment transport, as well as the impact of anthropogenic interferences such as damming the Nile River Flow. The reduction of the sediment input from the Nile River has somehow altered the geochemical signature of the inner shelf sediments. The REE patterns indicate weathering in areas subjected to erosion, while trace elements and major oxides spatial and temporal distributions concentrate eastwards under the influence of the easterly sediment transport pattern. Nile Delta inner shelf presented a typical case for understanding the link between geochemistry and sedimentary processes in nearshore and deltaic systems
Testifying the Aquifer Response Under the Stress of Different Scenarios of an Expected Shortage of Surface Water: Case Study South Eastern Nile Delta Fringes, Egypt
Groundwater is considered one of the important sources in Egypt. However, it is expected to face many challenges in the next few decades. The Eastern Nile delta fringes region, the current area of interest, is one of the most highly developed areas in Egypt for more than three decades. Special attention will be given to the existing large reclamation lands (surface water/groundwater) in the high desert lands and low ones which are adjacent and surrounding the Ismailia canal. Under the expected stress of extensive shortage in surface water of the Nile water system, as a result of the construction of GERD, the rapid population and urbanization, a direct impact on the groundwater system in terms of groundwater levels and water budget will be expected. The main research question of the present study is: what is the response of the Nile Delta Aquifer in the south Eastern Nile Delta Fringes in the case of crisis for the sustainability of existing large projects? Visual MODFLOW was used to simulate the existing condition of the irrigation canals and the expected changes under different scenarios of water shortage. The model was simulated and calibrated for the initial hydrogeological conditions throughout the period (1992-2015). The model was tested for scenarios based on the final calibration as an initial condition. Four scenarios were proposed and simulated for the calibrated regional groundwater model at the study area to evaluate and predict the response of the quaternary aquifer during the decrease of surface water levels for 20 years. These scenarios are: 1. Decrease of the surface water levels by 10% against drainage surplus this expression represents the net recharge to the aquifer all the year, 2. Decrease of the surface water levels by 10% against seasonal drainage surplus for six months (summer, winter), 3. Decrease of the surface water levels by 20% against drainage surplus all the year and 4. Decrease of the surface water levels by 20% against seasonal drainage surplus for six months (summer, winter). The results of simulated scenarios showed a change and fluctuation in the groundwater levels, while the maximum value of the change in storage was found in scenario 4.in which this value was decreased by 52.9 % between 2017 and 2037. but in all scenarios, the change in storage of the aquifer still stable and continuously increase, by 36.5% under scenario 2 and 29 % under scenario 4. This volume of storage will be available for pumping by extraction wells in case of surface water reduction. Keywords: Groundwater, Surface water, GERD, water budget, change in storage. DOI: 10.7176/CER/13-3-04 Publication date:May 31st 202
Land Use /Land Cover Change Detection Analysis for Eastern Nile Delta Fringes, Egypt
Egypt has turned its attention to develop many new areas for agricultural development, such as the fringes of the Nile Valley, the eastern, western fringes of the Nile Delta, and also to the desert areas. In this research, integration of GIS and remote sensing (RS&GIS) were used in the South Eastern Nile delta region to follow the change in land use/cover and to assess the change in the agricultural lands in the desert areas. Three satellite images for years 1992, 2002, 2015 were used to produce the land use/cover maps using the maximum likelihood method by selecting five classes for land cover as (Agricultural, water, desert, and urban). The results of the accuracy assessment were evaluated as 85%, 86.2%, and 87.5% for the years 1992, 2002, and 2015. The change detection maps were produced between (1992-2002), (2002-2015) and (1992-2015). To follow up the increase in reclaimed areas that previously planned for reclamation by the National Water Resources Plans. More change detection statistics were performed. The results showed an increase in the area of agricultural lands within the desert regions, with values that are aligned with the areas proposed in the previous national water plans. The area of reclamation lands of the existing reclamation projects started before 1992 increased by 17527.6 (feddan) from the year 1992 to 2015 compared to 115436 feddan for the reclamation lands planned by the Land master plan from (1992 to 2017) for the same period of years. Finally, we can consider the integration between GIS and remote sensing data as an important and powerful tool for accurately detection land use/land cover changes over the study area. Also, these tools were considered very useful for the planning of sustainable management for water resource plans. Keywords: Geographical Information Systems (GIS), Remote Sensing (RS), Land-use/ cover, change detection, the South Eastern Nile delta region. DOI: 10.7176/JEES/10-10-07 Publication date:October 31st 202
Tin complexes of 4-(Benzylideneamino)benzenesulfonamide: synthesis, structure elucidation and their efficiency as PVC photostabilizers
Poly(vinyl chloride) (PVC) suffers from photo-oxidation and photodegradation when exposed to harsh conditions. Application of PVC thus relies on the development of ever more efficient photostabilizers. The current research reports the synthesis of new complexes of tin and their assessment as poly(vinyl chloride) photostabilizers. The three new complexes were obtained in high yields from reaction of 4-(benzylideneamino)benzenesulfonamide and tin chlorides. Their structures were elucidated using different tools. The complexes were mixed with poly(vinyl chloride) at a very low concentration and thin films were made from the blends. The effectiveness of the tin complexes as photostabilizers has been established using a variety of methods. The new tin complexes led to a decrease in weight loss, formation of small residues, molecular weight depression, and surface alteration of poly(vinyl chloride) after irradiation. The additives act by absorption of ultraviolet light, removal the active chlorine produced through a dehydrochlorination process, decomposition of peroxides, and coordination with the polymeric chains. The triphenyltin complex showed the greatest stabilizing effect against PVC photodegradation as a result of its high aromaticity
Investigation of the impact of chemical modifications on the photostability of polymethyl methacrylate
For practical application, it is crucial to ensure that polymeric materials are protected against degradation due to aging and ultraviolet (UV) irradiation. A range of advancements in developing novel photostabilizers has been made in the last few years. Another approach is the alteration of polymer structures to enhance their ability to resist photodegradation and photooxidation on exposure to UV light for extended periods in harsh conditions. Polymeric chain modifications have proved to be efficient in increasing the photostability of materials. The current work deals with the surface functionalization of polymethyl methacrylate (PMMA) by incorporating organotin moieties on the polymer backbone. PMMA reacts with ethylenediamine to attach amino groups to the polymer chains. The amino group reacts with 2-hydroxynaphthaldehyde to produce the corresponding Schiff base. Adding trisubstituted (methyl, butyl, and phenyl) tin chloride led to the addition of organometallic residence to the polymeric chains. Thin films of the modified PMMA were made and irradiated with ultraviolet light for long durations to test the effect of chain modification on the photostability of polymeric materials. The effect of the substituent on the tin atom on the photostability of PMMA has been analyzed. Various methods were used for assessment, including infrared spectroscopy, weight loss, surface morphology, and roughness factor. The modified polymers showed increased resistance to photodegradation and had lower roughness factor, weight reduction, surface damages, and small fragments generated compared to the blank PMMA. The polymer containing phenyl substituents showed the most apparent photostabilization effect and the least destructive changes in the PMMA surface on photoirradiation
Self-Nanoemulsifying Drug Delivery System Loaded with Psiadia punctulata Major Metabolites for Hypertensive Emergencies: Effect on Hemodynamics and Cardiac Conductance
Vasodilators are an important class of antihypertensive agents. However, they have limited clinical use due to the reflex tachycardia associated with their use which masks most of its antihypertensive effect and raises cardiac risk. Chemical investigation of Psiadia punctulata afforded five major methoxylated flavonoids (1–5) three of which (1, 4, and 5) showed vasodilator activity. Linoleic acid-based self-nanoemulsifying drug delivery system (SNEDDS) was utilized to develop intravenous (IV) formulations that contain compounds 1, 4, or 5. The antihypertensive effect of the prepared SNEDDS formulations, loaded with each of the vasodilator compounds, was tested in the angiotensin-induced rat model of hypertension. Rats were subjected to real-time recording of blood hemodynamics and surface Electrocardiogram (ECG) while the pharmaceutical formulations were individually slowly injected in cumulative doses. Among the tested formulations, only that contains umuhengerin (1) and 5,3′-dihydroxy-6,7,4′,5′-tetramethoxyflavone (5) showed potent antihypertensive effects. Low IV doses, from the prepared SNEDDS, containing either compound 1 or 5 showed a marked reduction in the elevated systolic blood pressure by 10 mmHg at 12 μg/kg and by more than 20 mmHg at 36 μg/kg. The developed SNEDDS formulation containing either compound 1 or 5 significantly reduced the elevated diastolic, pulse pressure, dicrotic notch pressure, and the systolic–dicrotic notch pressure difference. Moreover, both formulations decreased the ejection duration and increased the non-ejection duration while they did not affect the time to peak. Both formulations did not affect the AV conduction as appear from the lack of effect on p duration and PR intervals. Similarly, they did not affect the ventricular repolarization as no effect on QTc or JT interval. Both formulations decreased the R wave amplitude but increased the T wave amplitude. In conclusion, the careful selection of linoleic acid for the development of SNEDDS formulation rescues the vasodilating effect of P. punctulata compounds from being masked by the reflex tachycardia that is commonly associated with the decrease in peripheral resistance by most vasodilators. The prepared SNEDDS formulation could be suggested as an effective medication in the treatment of hypertensive emergencies, after clinical evaluation
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