Nanosheet composed of gold nanoparticle/graphene/epoxy resin based on ultrasonic fabrication for flexible dopamine biosensor using surface-enhanced Raman spectroscopy

Hussein Mahmoud A.,El-Said Waleed A.,Abu-Zied Bahaa M.,최정우 나노기술연구협의회 2020 Nano Convergence Vol.7 No.15

Construction of a fast, easy and sensitive neurotransmitters-based sensor could provide a promising way for the diagnosis of neurological diseases, leading to the discovery of more effective treatment methods. The current work is directed to develop for the first time a flexible Surface-Enhanced Raman Spectroscopy (SERS) based neurotransmit‑ ters sensor by using the ultrasonic-assisted fabrication of a new set of epoxy resin (EPR) nanocomposites based on graphene nanosheets (GNS) using the casting technique. The perspicuous epoxy resin was reinforced by the variable loading of GNS giving the general formula GNS/EPR 1–5 . The designed products have been fabricated in situ while the perspicuous epoxy resin was formed. The expected nanocomposites have been fabricated using 3%, 5%, 10%, 15% and 20% GNS loading was applied for such fabrication process. The chemical, physical and morphological properties of the prepared nanocomposites were investigated by using Fourier transforms infrared spectroscopy, X-ray diffrac‑ tion, Thermogravimetric analysis, Differential Thermal gravimetry, and field emission scanning electron microscopy methods. The GNS/EPR 1–5 nanocomposites were decorated with a layer of gold nanoparticles (Au NPs/GNS/EPR) to create surface-enhanced Raman scattering hot points. The wettability of the Au NPs/GNS/EPR was investigated in comparison with the different nanocomposites and the bare epoxy. Au NPs/GNS/EPR was used as a SERS-active surface for detecting different concentrations of dopamine with a limit of detection of 3.3 µM. Our sensor showed the capability to detect low concentrations of dopamine either in a buffer system or in human serum as a real sample.

Solution of randomly excited stochastic differential equations with stochastic operator using spectral stochastic finite element method (SSFEM)

Hussein A.,El-Tawil M.,El-Tahan W.,Mahmoud, A. A. 국제구조공학회 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.28 No.2

This paper considers the solution of the stochastic differential equations (SDEs) with random operator and/or random excitation using the spectral SFEM. The random system parameters (involved in the operator) and the random excitations are modeled as second order stochastic processes defined only by their means and covariance functions. All random fields dealt with in this paper are continuous and do not have known explicit forms dependent on the spatial dimension. This fact makes the usage of the finite element (FE) analysis be difficult. Relying on the spectral properties of the covariance function, the Karhunen-Loeve expansion is used to represent these processes to overcome this difficulty. Then, a spectral approximation for the stochastic response (solution) of the SDE is obtained based on the implementation of the concept of generalized inverse defined by the Neumann expansion. This leads to an explicit expression for the solution process as a multivariate polynomial functional of a set of uncorrelated random variables that enables us to compute the statistical moments of the solution vector. To check the validity of this method, two applications are introduced which are, randomly loaded simply supported reinforced concrete beam and reinforced concrete cantilever beam with random bending rigidity. Finally, a more general application, randomly loaded simply supported reinforced concrete beam with random bending rigidity, is presented to illustrate the method.

<i>Commiphora molmol</i> Modulates Glutamate-Nitric Oxide-cGMP and Nrf2/ARE/HO-1 Pathways and Attenuates Oxidative Stress and Hematological Alterations in Hyperammonemic Rats

Mahmoud, Ayman M.,Alqahtani, Sultan,Othman, Sarah I.,Germoush, Mousa O.,Hussein, Omnia E.,Al-Basher, Gadh,Khim, Jong Seong,Al-Qaraawi, Maha A.,Al-Harbi, Hanan M.,Fadel, Abdulmannan,Allam, Ahmed A. Hindawi 2017 Oxidative medicine and cellular longevity Vol.2017 No.-

<P>Hyperammonemia is a serious complication of liver disease and may lead to encephalopathy and death. This study investigated the effects of <I>Commiphora molmol</I> resin on oxidative stress, inflammation, and hematological alterations in ammonium chloride- (NH<SUB>4</SUB>Cl-) induced hyperammonemic rats, with an emphasis on the glutamate-NO-cGMP and Nrf2/ARE/HO-1 signaling pathways. Rats received NH<SUB>4</SUB>Cl and <I>C. molmol</I> for 8 weeks. NH<SUB>4</SUB>Cl-induced rats showed significant increase in blood ammonia, liver function markers, and tumor necrosis factor-alpha (TNF-<I>α</I>). Concurrent supplementation of <I>C. molmol</I> significantly decreased circulating ammonia, liver function markers, and TNF-<I>α</I> in hyperammonemic rats. <I>C. molmol</I> suppressed lipid peroxidation and nitric oxide and enhanced the antioxidant defenses in the liver, kidney, and cerebrum of hyperammonemic rats. <I>C. molmol</I> significantly upregulated Nrf2 and HO-1 and decreased glutamine and nitric oxide synthase, soluble guanylate cyclase, and Na<SUP>+</SUP>/K<SUP>+</SUP>-ATPase expression in the cerebrum of NH<SUB>4</SUB>Cl-induced hyperammonemic rats. Hyperammonemia was also associated with hematological and coagulation system alterations. These alterations were reversed by <I>C. molmol</I>. Our findings demonstrated that <I>C. molmol</I> attenuates ammonia-induced liver injury, oxidative stress, inflammation, and hematological alterations. This study points to the modulatory effect of <I>C. molmol</I> on glutamate-NO-cGMP and Nrf2/ARE/HO-1 pathways in hyperammonemia. Therefore, <I>C. molmol</I> might be a promising protective agent against hyperammonemia.</P>

Deuteromycols A and B, Two Benzofuranoids from a Red Sea Marine-derived Deuteromycete sp.

Mahmoud Nawwar,Sahar Hussein,Nahla A Ayoub,Amani Hashim,Gudrun Mernitz,Beate Cuypers,Michael Linscheid,Ulrike Lindequist 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.11

Two benzofuranoids, deuteromycol A, 6,7-dihydroxy-2-[1'-hydroxy-(1'→5'')-2'',3'',4''-trihydroxy-2'',3''-dihydropyran]benzofuran and deuteromycol B, 1-(6,7-dihydroxy benzofuran-2-yl)methylacetate have been isolated from the ethanol extract of the marine-derived fungal strain MF003 (Deuteromycete) obtained from Red Sea mangrove drift wood. Deuteromycols A and B contain a catecholic nucleus that to the best of our knowledge is unusual in association with marine fungi secondary metabolites. Structures were established on the basis of extensive 1Dand 2D-NMR spectroscopic studies as well as on mass spectrometric analysis. Besides, the extracts exhibited in vitro antibacterial activity.

Synthesis of polyoxometalates supported on HZSM-5 for the photocatalytic purification of crude terephthalic acid under mild conditions

Hussein, A.M.,Mady, A.H.,Mahmoud, S.,Shim, J.-J.,Yehia, F.Z. Elsevier 2019 Journal of photochemistry and photobiology Chemist Vol.377 No.-

<P><B>Abstract</B></P> <P>Phosphomolybdic (PMo) and vanadium-containing phosphomolybdic (PV<SUB>2</SUB>Mo) acids were synthesized and supported on HZSM-5 zeolite via a wet impregnation technique and used as photocatalysts for the purification of terephthalic acid (TA) via an economic process. Nowadays, purified TA can be obtained from crude TA due to their great commercial importance by separating 4-carboxybenzaldehyde (4-CBA), which represents high environmental toxicity and negatively affects the applications of TA. For these reasons, conversion of 4-CBA to TA is highly desirable for both enhancing the efficiency of purified TA production and environmental reasons. The synthesized catalysts were characterized by XRD, FTIR, Raman spectroscopy, BET, SEM, and TEM. The purification process was carried out by under different parameters as VUV irradiation, persulfate (PS), time, and different types of catalysts (PMo or PV<SUB>2</SUB>Mo)/HZSM-5. This kind of combination showed complete removal of the 4-CBA with a high yield of PTA in 2 h. The high efficiency attributed to the acidity of the polyoxometalates/HZSM-5, which increase the selectivity to oxidize 4-CBA at room temperature and much shorter reaction time compared to other common methods.</P> <P><B>Highlights</B></P> <P> <UL> <LI> PMo or PV<SUB>2</SUB>Mo / HZSM-5 used as a photocatalyst for the economic purification of CTA. </LI> <LI> Catalyst achieve complete purification for CTA at 2 h and at room temperature. </LI> <LI> PV<SUB>2</SUB>Mo/HZSM-5 show no significant loss of catalytic activity for four consecutive. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Site adaptations of Acanthogyrus (Acanthosentis) tilapiae: Observations through light and scanning electron microscopy

Mahmoud E. Bayoumy,Osman K. Abd El-Hady,Hussein A.M. Osman 대한수의학회 2006 Journal of Veterinary Science Vol.7 No.4

Acanthogyrus (Acanthosentis) tilapiae parasites were collected from the intestines of 300 fish belonging to three tilapia species sourced at the River Nile, Giza, Egypt. The proboscis of the parasite was characterized by three rows of hooks that curved towards the posterior of the body. The first row is supported by unmodified hooks. The parasite tegument has a series of alternative folds and a large number of pores. Sensory ganglia are located on the surface of the proboscis and body. Acanthogyrus (Acanthosentis) tilapiae provokes an aggressive host response indicated by hyperplasia of the intestinal goblet cells and focal eosinophil infiltrations. This acanthocephalan parasite shows a highly modified adaptation to its site of host infection.

Polyphenolic Metabolites of the Flowers of Tamarix tetragyna

Sahar A. M. Hussein,Mahmoud A. M. Nawwar,Amani M. D. El Mousallami 한국생약학회 2000 Natural Product Sciences Vol.6 No.4

Phytochemical study of the constitutive polyphenolics of the flower aqueous alcohol extract of Tamarix tetragyna was carried out. The new sulphated flavonol, quercetin 3`,4`-dimethyl ether 3-O-KSO₃ as well as the new natural galloyl glucose, 2-O-galloyl-(α.β)⁴-⁴C₁-glucopyranose were isolated and characterised. The known sulphated flavonols, kaempferol 7,4-dimethyl ether 3,5-di-O-KSO₃, quercetin 7-methyl ether 3,3`,4`-tri-O-KSO₃, quercetin 7,4`-dimethyl ether 3-O-KSO₃ and quercetin 3-O-KSO₃ and the known sulphated phenolics, isoferulic acid 3-O-KSO₃ and ellagic acid 4,4`-dimethyl ether 3-O-KSO₃ were also separated and identified. The structures were established by conventional methods of analysis and confirmed by ¹H-, ¹³C-NMR and negative ESI-mass spectrometry. 2D-homonuclear chemical shift correlation NMR experiment was applied for the new natural galloylglucose.

Unique Phenolic Sulphate Conjugates from the Flowers of Tamarix amplexicaulis

Sahar A. M. Hussein,Amani M. D. El-Mousallamy,Mahmoud A. M. Nawwar,Ahmed A. M. Souleman,Heba H. Barakat 한국생약학회 1998 Natural Product Sciences Vol.4 No.4

The unique sulphated phenolics, gallic acid 3-methyl ether 5-potassium sulphate, isoferulic acid 3-potassium sulphate, and ellagic acid 4,4`-dimethyl ether 3-potassium sulphate have been isolated from the flowers of Tamarix amplexicaulis Ehrenb. (Tamaricaceae). The hitherto unknown natural phenolic acid, gallic acid 3-methyl ether, together with the known phenolic, gallic acid, gallic acid 4-methyl ether, isoferulic acid, ferulic acid, ellagic acid, and ellagic acid 4,4`-dimethyl ether have been also separated and characterized. The structures were established by conventional methods, including electrophoretic analysis and confirmed by ESIMS, ¹H- and ¹³C-NMR.

Comparison of Laser In Situ Keratomileusis Flap Morphology and Predictability by WaveLight FS200 Femtosecond Laser and Moria Microkeratome: An Anterior Segment Optical Coherence Tomography Study

Zeiad H,Eldaly,Mahmoud A,Abdelsalam,Mohamed S,Hussein,Mohamed A,Nassr 대한안과학회 2019 Korean Journal of Ophthalmology Vol.33 No.2

Purpose: To evaluate laser in situ keratomileusis (LASIK) flap thickness predictability and morphology by femtosecond (FS) laser and microkeratome (MK) using anterior segment optical coherence tomography. Methods: Fifty-two candidates for the LASIK procedure were stratified into two groups: FS laser-assisted (Allegretto FS-200) and MK flap creation (Moria 2). Flap thickness was determined at five points. The side-cut angle was measured in three directions at the margin interface. LASIK flap assessment was performed one month postoperatively by Spectralis anterior segment optical coherence tomography. Results: Fifty-two patients (93 eyes) were recruited; 49 eyes were stratified to the FS group and 44 eyes to the MK group. The FS group had relatively even flap configurations, and the MK group had meniscus-shaped flaps. Mean differences between planned and actual flap thickness were 12.93 ± 8.89 and 19.91 ± 5.77 μm in the FS and MK groups, respectively. In thin flaps (100 to 110 μm), there was a significant disparity between the two groups (7.80 ± 4.71 and 19.44 ± 4.46 μm in the FS and MK groups, respectively). However, in thicker flaps(130 μm), comparable flap thickness disparity was achieved (18.54 ± 9.52 and 20.83 ± 5.99 μm in the FS and MK groups, respectively). Mean side-cut angle was 74.29 ± 5.79 degrees and 32.34 ± 4.94 degrees in the FS and MK groups, respectively. Conclusions: Comparable flap thickness predictability was achieved in thicker flaps (130 μm), while the FS laser technique yielded a more predictable result in thinner flaps (100 to 110 μm). Different flap morphology was observed in meniscus flaps in MK-LASIK and flap morphology in FS-LASIK.

Comparison of Laser In Situ Keratomileusis Flap Morphology and Predictability by WaveLight FS200 Femtosecond Laser and Moria Microkeratome: An Anterior Segment Optical Coherence Tomography Study

Zeiad H. Eldaly,Mahmoud A. Abdelsalam,Mohamed S. Hussein,Mohamed A. Nassr 대한안과학회 2019 Korean Journal of Ophthalmology Vol.33 No.2

Purpose: To evaluate laser in situ keratomileusis (LASIK) flap thickness predictability and morphology by femtosecond(FS) laser and microkeratome (MK) using anterior segment optical coherence tomography. Methods: Fifty-two candidates for the LASIK procedure were stratified into two groups: FS laser-assisted (AllegrettoFS-200) and MK flap creation (Moria 2). Flap thickness was determined at five points. The side-cutangle was measured in three directions at the margin interface. LASIK flap assessment was performed onemonth postoperatively by Spectralis anterior segment optical coherence tomography. Results: Fifty-two patients (93 eyes) were recruited; 49 eyes were stratified to the FS group and 44 eyes to theMK group. The FS group had relatively even flap configurations, and the MK group had meniscus-shapedflaps. Mean differences between planned and actual flap thickness were 12.93 ± 8.89 and 19.91 ± 5.77 μm inthe FS and MK groups, respectively. In thin flaps (100 to 110 μm), there was a significant disparity between thetwo groups (7.80 ± 4.71 and 19.44 ± 4.46 μm in the FS and MK groups, respectively). However, in thicker flaps(130 μm), comparable flap thickness disparity was achieved (18.54 ± 9.52 and 20.83 ± 5.99 μm in the FS andMK groups, respectively). Mean side-cut angle was 74.29 ± 5.79 degrees and 32.34 ± 4.94 degrees in the FSand MK groups, respectively. Conclusions: Comparable flap thickness predictability was achieved in thicker flaps (130 μm), while the FS lasertechnique yielded a more predictable result in thinner flaps (100 to 110 μm). Different flap morphology wasobserved in meniscus flaps in MK-LASIK and flap morphology in FS-LASIK.