1,005 research outputs found
A luminescent metal-organic framework composite as a turn-on sensor for the selective determination of monosodium glutamate in instant noodles
Get PDFThis work reports the development and application of a new fluorescent nanoprobe sensor depending on using luminescent metal organic framework (LMOF). The developed sensor composed of hybridized Ca 1,3,5-benzenetricarboxylic acid metal organic framework with microcrystalline cellulose (Ca-BTC/MCC MOF) as a fluorescent probe for the determination of the monosodium glutamate (MSG), a non-chromophoric food additive. Thе dеvеlopеd sеnsor was characterized using a high-rеsolution scanning еlеctron microscopе (HR-SЕM), X-ray diffraction (XRD), and Fouriеr transform infrared spеctroscopy (FTIR). Thе Ca-BTC/MCC MOF hybrid, еxaminеd undеr thе HR-SЕM, showеd morphological fеaturеs diffеrеnt from thе MCC and thе Ca-BTC MOF. Thе diffraction pattеrns of Ca-BTC/MCC composites clearly displayed thе characteristic Ca-BTC MOF diffraction bands, indicating that MCC was succеssfully incorporatеd in thе formation of crystalline MOF hybrids. Thе FTIR spеctra show thе bands of MCC, as well as the bands of Ca-BTC MOFs. The prepared nanoprobe was successfully applied as a sensitive sensor for the determination of MSG in food sample. The method was validated following the International ICH (Q2)R2 guidelines in terms of precision, trueness and other main analytical figures of merit, comprised the green profile and practicability metrics. A wide linearity range was achieved (5-50 μg/mL) with good correlation coefficient (R2≥0.9993). The recoveries (%) were found in the range of 100.0 to 101.5 and the RSDs (%) were in the range of 0.1 to 0.9%.
These results show that the developed nanoprobe was selective, and highly accurate to determine this important food additive in the seasonings of instant noodles, also showing a reduced environmental impact based on the metrics currently accepted for the evaluation of the green profile and practicability
sj-docx-1-opp-10.1177_10781552231192516 - Supplemental material for Optimizing cyclosporine A dose post allogeneic hematopoietic stem cell transplantation in paediatric cancer patients
No full textSupplemental material, sj-docx-1-opp-10.1177_10781552231192516 for Optimizing cyclosporine A dose post allogeneic hematopoietic stem cell transplantation in paediatric cancer patients by Mennatallah Elnaggar, Hanafy Hafez, Amr Abdallah, Mahmoud Hamza, Marwa M. Khalaf and Alaa El-Haddad in Journal of Oncology Pharmacy Practice</p
Applications of layered double hydroxides in sample preparation: A review
No full textMicroextraction is a technique that can be used to selectively extract substances from a complex matrix using small amounts of extracting agents and/or solvents. The technique can be broadly classified into liquid- and solid-phase microextraction methods, according to the specific nature of the system. The principle of the solid-phase microextraction (SPME) is founded on selective equilibrium-based extraction of compounds using a microporous adsorbent that acts as a solid phase extraction (SPE) sorbent. In recent years, there has been growing interest in the use of layered double hydroxides (LDHs) as microextraction sorbents. The main advantages of using LDHs are their high surface area to volume ratio, low operating pressure, and simplicity of fabrication and purification. They are also relatively inert and easy to purify by simple washing. Several recent studies have shown that LDHs are good candidates for drug delivery, catalysis, environmental remediation, energy storage and chemical analysis. The use of LDH in analytical chemistry includes sensing, electrochemical analysis, and extraction. In this review, the roles of LDHs in solid phase extraction and microextraction including dispersive-solid phase microextraction (dSPME), in-tube solid phase microextraction (IT-SPME), headspace solid phase microextraction (HS-SPME), stir bar sorptive extraction (SBSE) and thin film microextraction (TFME) were discussed. The preparation, characterization, regeneration and analytical performances/applications were also discussed
Metal Organic Framework-Derived Carbon Nanomaterials and MOF hybrids for Chemical Sensing
No full textCarbon nanomaterials (CNMs) have attracted widespread attention in different fields due to their superior capabilities in terms of adsorption, enhanced oxidation, and photocatalysis. CNMs are safer and more eco-friendly than organic compounds, which could explain the growing interest in developing new chemosensors using CNMs. Metal-organic frameworks (MOFs) have been widely used in many applications due to their regular network structure, adaptable morphology, porous nature, and large specific surface area. However, most MOFs are unstable in aqueous solutions due to self-decomposition, which could limits their applications in chemical sensing. Several attempts have been reported to increase the stability of MOFs in water-based matrices through chemical modifications using stable entities such as CNMs via MOF hybridization or carbonization. MOF hybrids retain their original shape and structure, and their stability depends on the MOF type, while MOF-derived CNMs undergo drastic changes in shape and structure. This review discusses the recent trends and applications of MOF-derived CNMs and MOF-hybrids in chemical sensing. Hybridization of MOFs using graphene, carbon fibers, carbon nanotubes and carbon quantum dots are described with emphasis on their role and applications in chemosensors
Smart Partial Flooding Routing Algorithms for 3D Ad Hoc Networks
No full textAbstractMobile ad-hoc networks (MANETs) become an essential part of the current wireless communication infrastructure, thus efficient routing protocols takes an important consideration of the current research. In Geographic-Based routing algorithms, nodes use the location information about nodes to take routing choices. Current geographical routing algorithms usually address the routing environment in 2D space. However, in real life, nodes could be located in 3D space. In this paper, we propose two 3D geographical routing algorithms that uses the advantage of the high delivery rate of the flooding algorithms and the low overhead of the progress-based routing algorithms. The first algorithm (Progress-SGFlooding) uses geographical routing to progress as much as possible to the destination, if its not possible, a partial flooding is used over a sub-graph extracted locally. The second algorithm (Progress- SGFlooding-Progress) used geographical routing to progress to the destination, if the progress is not possible, a partial flooding is used over a sub-graph for one step only and then the algorithm goes back to the geographical routing. We evaluate our algorithm and compare it with current routing algorithms. The simulation results show a significant improvement in delivery rate up to 100% compared to 70% and a huge reduction in overall traffic around 60%
Supplément au Catalogue des inscriptions latines païennes du Musée du Bardo. [Inscriptions funéraires inédites de provenance inconnue]
No full textThe author presents 71 unpublished pagan epitaphs kept in the Bardo national Museum (Tunis) and whose provenience is still unknown. As some names appear for the first time in African epigraphy, the major interest of this catalogue deak with onomastics.L' A. publie 71 épitaphes païennes inédites, conservée au Musée national du Bardo (Tunis) et dont l'origine demeure inconnue. Certains noms apparaissant pour la première fois dans l'épigraphie africaine, l'intérêt de ce catalogue est avant tout d'ordre onomastique.Benzina Ben Abdallah Zeïneb. Supplément au Catalogue des inscriptions latines païennes du Musée du Bardo. [Inscriptions funéraires inédites de provenance inconnue]. In: Antiquités africaines, 32,1996. pp. 113-143
Corrigendum: Concurrent use of oral anticoagulants and sulfonylureas in individuals with type 2 diabetes and risk of hypoglycemia: a UK population-based cohort study
Get PDFIn the published article, there was a mistake in the affiliation for “Alaa Alsharif.” The affiliation for “Alaa Alsharif” was displayed as “Research Department of Practice and Policy, School of Pharmacy, University College London, London, United Kingdom.” The correct affiliation is “Department of Pharmacy Practice, College of Pharmacy, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia.” The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated
Deployment of MOOCs in Virtual Joint Academic Degree Programs
No full textThis research paper investigates the readiness of students to opt for MOOC courses in universities offering a joint master degree international programme. A study is conducted on two joint academic study programs offered by the University of Hasselt in Belgium and Princess Sumaya University for Technology in Jordan. The study examines the readiness of students to take MOOC courses and their acceptance by universities' management staff and professors. The study reveals promising results as the results suggest that such virtual study programs are readily accepted in both universities by professors and students. On the other hand, management staff and some professors expressed concerns on the approval of the equivalence of a MOOC onto courses.Sammour, G (corresponding author), Princess Sumaya Univ Technol PSUT, Dept Business Informat Technol, Amman, Jordan
Synergistic Anti Leukemia Effect of a Novel Hsp90 and a Pan Cyclin Dependent Kinase Inhibitors
Get PDFAcute myeloid leukemia (AML) is among the top four malignancies in Saudi nationals,
and it is the top leukemia subtype worldwide. Resistance to available AML drugs requires the
identification of new targets and agents. Hsp90 is one of the emerging important targets in AML,
which has a central role in the regulation of apoptosis and cell proliferation through client proteins
including the growth factor receptors and cyclin dependent kinases. The objective of the first part of
this study is to investigate the putative Hsp90 inhibition activity of three novel previously
synthesized quinazolines, which showed HL60 cytotoxicity and VEGFR2 and EGFR kinases
inhibition activities. Using surface plasmon resonance, compound 1 (HAA2020) showed better Hsp90
inhibition compared to 17-AAG, and a docking study revealed that it fits nicely into the ATPase site.
The objective of the second part is to maximize the anti-leukemic activity of HAA2020, which was
combined with each of the eleven standard inhibitors. The best resulting synergistic effect in HL60
cells was with the pan cyclin-dependent kinases (CDK) inhibitor dinaciclib, using an MTT assay.
Furthermore, the inhibiting effect of the Hsp90α gene by the combination of HAA2020 and dinaciclib
was associated with increased caspase-7 and TNF-α, leading to apoptosis in HL60 cells. In addition,
the combination upregulated p27 simultaneously with the inhibition of cyclinD3 and CDK2, leading
to abolished HL60 proliferation and survival. The actions of HAA2020 propagated the apoptotic and
cell cycle control properties of dinaciclib, showing the importance of co-targeting Hsp90 and CDK,
which could lead to the better management of leukemia
Optimization of stiffened panels using a combination of FEM and a predictor-corrector interior point method
No full textStructural optimization, first introduced by Schmidt in 1960, is a rapid growing factor in the development of new aerospace structures. This growth is established by the increase in numerical modelling techniques, cheaper computer power, the increasing cost of production and competition between companies. The combination of both structural optimization and finite element software allowed for the rise of new and more efficient optimization methods provided that the software can performsensitivity analysis. Many programs used in industry today such as BOSS Quattro , PASCO and VICONOPT restrict themselves to basic optimization methods. The goal now is to develop an optimizer for stiffened panels, using a combination of FEM and a more advanced optimization method. Interior point methods have been proven to be more efficient than primal-dual methods for solving sub-problems. Therefore Mehrotra’s predictor-corrector interior point method is used in the version of Zillober. To reach convergence convex approximations are required. The conservative approximation from Fleury’s ConLin provides the basis of many other more advance approximation methods. Therefore this method is chosen to form the initial optimizer. A 2D The FEM model is established using shell and bar elements for the panel and stiffeners respectively. This allows for easy adjustment of the geometry without the need to change the model itself. The bar element properties are defined by the PBAR card rather than the PBARL card in NASTRAN. This avoids the input of fixed NASTRAN specified cross sections with limited design freedom. The sensitivities with respect to stiffener properties are extracted from NASTRAN. These are then converted to the required sensitivities using analytical equations. With all the necessary information available, the inner loop of the optimization process is initiated. Approximations of the constraints, objective and sensitivities are produced. Based on the approximations, the predictor step establishes a maximum step size, which is then adjusted by the corrector step to a more feasible one. This is done iteratively until the duality gap is below a specified limit. Finally a new outer iteration can start if no convergence is reached. Three goals were achieved by analysing of 11 test cases. First the optimizer shows that it can handle different property sets for the stiffeners within the same panel. Secondly, the optimization works for different cross sections. Finally, when performed for similar panels with a different amount of stiffeners, an optimal number is found. The optimization is performed for minimum weight while limited by stress, buckling and design constraints. The results indicate that for 8 out of 11 cases convergence is reached within 12 cycles. Due oscillatory behaviour two other cases converged relatively slow and one did not converge at all. This happens due to the incapability of the optimizer to consider new buckling modes establishing with the adjustment of the parameters. In the end however all three statements were proven outside of the three oscillating cases. For the model that was defined, the optimal amount of stiffeners is 7. Additionally I-beam stiffener provided the most consistent performance with respect to convergence. Finally for this case, although optimizing for different stiffener properties per panel lead to a small reduction in weight, it is not worth the computational effort. So it can be concluded that the optimizer works. On top of this the restrictions on the cross-section defined by NASTRAN were eliminated by extracting a different set of sensitivities and adjusting them using analytical equations. This leads to an optimizer, which can perform size and shape optimization by use of NASTRAN analyses, analytical transformations and an interior point optimization method.Aerospace Structures and Computational MechanicsMechanics, Aerospace Structures & MaterialsAerospace Engineerin
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