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Technology optimization of chitosan production from Aspergillus niger biomass and its functional activities

Research Abstract
There is a growing demand for chitosan production from fungi as it provides superior physico-chemical properties over traditional crustacean sources. Chitosan was recovered from Aspergillus niger biomass using different conditions of alkali deproteinization and Box-Benhken experimental design was evaluated to study the influence of alkali concentration, temperature and time on chitosan yield, degree of deacetylation (DD) and molecular weight (MW). Chitosan with different physico-chemical properties was obtained under different combinations of extraction factors. Desirability function was then used to predict the best overall combinations of responses. The most desirable compromise allowed for the recovery of chitosan with a yield of 7.0% (w/w), DD 83.64% and MW 2.70 × 104 Da, which were in good agreement with the predicted values. The recovered chitosan exhibited a good hydroxyl radical scavenging activity and ferrous ions chelating ability reached to 82.40% and 87.23%, respectively. Additionally, it demonstrated good emulsion stabilizing capacities with different vegetable oils. The results suggest that fungal mycelia can be used as a promising source of chitosan with important physico-chemical properties suitable for several applications such as food, pharmaceutical, and cosmetic industries.
Research Authors
Khayria M Abdel-Gawad, Awatief F Hifney, Mustafa A Fawzy, Mohamed Gomaa
Research Journal
Food Hydrocolloids
Research Pages
593-601
Research Publisher
Elsevier
Research Rank
1
Research Vol
63
Research Website
http://www.sciencedirect.com/science/article/pii/S0268005X16305215
Research Year
2017

Label‐free Electrochemical Sensor for Ex‐vivo Monitoring of Alzheimer's Disease Biomarker

Research Abstract
The beta-amyloid (Aβ) peptide was used as an important biomarker for Alzheimer's disease (AD) diagnosis. The development of an accurate, selective, rapid, and highly sensitive technique for detecting of Aβ level is an important issue in biology, and medicine to assess human health risks. Here, gold nanoparticles (Au NPs) with different size were electrochemically deposited onto the indium tin oxide (ITO) substrate in the presence of different molecular weights of surfactants. The modified substrates were used as a high sensitive electrochemical sensor of in-vitro as well as ex-vivo monitoring of Aβ based on cyclic voltammetry and square wave voltammetry techniques. Our findings revealed that the modification of ITO electrode with Au NPs could enhance its sensor performance with high sensitivity for low concentration levels of Aβ over a wide linear range with a detection limit of about 20.7 ng/g, which is less than the concentration of insoluble Aβ40 (105.4±40.2 μg/g) in brain of AD induced. In addition, Au NPs/ITO modified electrodes have demonstrated ability to monitor Aβ in the brain extracted samples without any potential interference with other components. Raman spectroscopy has been used to confirm the presence of Aβ in the AD-induced samples. Thus, it is applicable for analyzing ex-vivo samples.
Research Authors
Waleed A. El-Said, Kawthar Abd El-Hameed, Nagwa Abo El-Maali, Hayam G. Sayyed
Research Journal
Electroanalysis
Research Pages
PP.748-755
Research Publisher
NULL
Research Rank
1
Research Vol
Vol.29
Research Website
NULL
Research Year
2017

Onion purple blotch symptoms, at Assiut Governorate (Egypt), caused by synergistic association between Alternaria porri and Stemphylium vesicarium

Research Abstract
The incidence of onion purple blotch disease was investigated at Assiut Governorate, Egypt during 2011. Lesions with typical symptoms of the disease were colonized by Alternaria porri, Stemphylium vesicarium or mixtures of the both pathogens comprising 2.6, 39.8 and 57.6 % of samples, respectively. Four isolates were selected for virulence evaluation according to the nature of isolation, whereas two isolates were individually associated with the diseased samples and two isolates were collectively recovered. Individually, A. porri AUMC9301 and AUMC10453 showed high virulence contributing 81.25 and 78.13 %, respectively. Also, S. vesicarium AUMC10512 and AUMC10519 exhibit severity comprising 37.50 and 25.00 %, respectively. On the other hand, mixture of A. porri AUMC10453 and S. vesicarium AUMC10519 exhibited highest virulence (91.50 %). In conclusion, this investigation proved that onion plants showing purple blotch symptoms mainly colonized by both A. porri and S. vesicarium. Consequently, increase in the disease may be attributed to the association between these pathogens.
Research Authors
Ismail R. Abdel-Rahim
Sobhy I. I. Abdel-Hafez
Kamal A. M. Abo-Elyousr
Research Journal
Journal of Plant Diseases and Protection
Research Pages
195-200
Research Publisher
springer.com
Research Rank
1
Research Vol
124
Research Website
http://link.springer.com/article/10.1007/s41348-016-0057-5
Research Year
2017

Nigella sativa seed protects against 4-nonylphenol-
induced haematotoxicity in Clarias gariepinus (Burchell, 1822): Oxidant/antioxidant rebalance

Research Abstract
4-Nonylphenol (NP) is an emerging concern contaminant which is widely spread in the aquatic ecosystem. Nigella sativa seed (NSS) has multifaceted therapeutic values. This study aimed to give insight into the potential protective effect of NSS on NP-induced haematotoxicity in Clarias gariepinus through evaluation of haematological parameters, oxidant/antioxidant balance of blood lysate and histopathological investigation of blood smear. One hundred and fifty fish were divided into five groups (30/group). First group served as control which did not received NP exposure and fed basal diet without NSS supplementation. The other four groups were exposed to NP at a dose of 0.1 mg L−1 and fed diets supplemented with NSS at levels of 0, 10, 25 and 50 g/kg diet, respectively. Macrocytic hypochromic anaemia, thrombocytopenia, leucopenia, neutrophilia, lymphopenia, monocytosis and eosinophilia were observed following NP exposure together with increase in morphological erythrocyte alterations and micronuclei formation. Elevation in total peroxide and malondialdehyde and depletion in total antioxidant capacity of blood lysate were reported. We concluded that supplementation of NSS markedly ameliorated the previously listed manifestations, and the most effective doses were 25 and 50 g/kg feed.
Research Authors
N.S. Abou Khalil1 | M. Abd-Elkareem2 | A.H. Sayed3
Research Journal
Aquaculture Nutrition
Research Pages
pp. 1-8
Research Publisher
wiley
Research Rank
1
Research Vol
Vol. 1
Research Website
http://onlinelibrary.wiley.com/doi/10.1111/anu.12522/abstract
Research Year
2017

Nigella sativa seed protects against 4-nonylphenol-
induced haematotoxicity in Clarias gariepinus (Burchell, 1822): Oxidant/antioxidant rebalance

Research Abstract
4-Nonylphenol (NP) is an emerging concern contaminant which is widely spread in the aquatic ecosystem. Nigella sativa seed (NSS) has multifaceted therapeutic values. This study aimed to give insight into the potential protective effect of NSS on NP-induced haematotoxicity in Clarias gariepinus through evaluation of haematological parameters, oxidant/antioxidant balance of blood lysate and histopathological investigation of blood smear. One hundred and fifty fish were divided into five groups (30/group). First group served as control which did not received NP exposure and fed basal diet without NSS supplementation. The other four groups were exposed to NP at a dose of 0.1 mg L−1 and fed diets supplemented with NSS at levels of 0, 10, 25 and 50 g/kg diet, respectively. Macrocytic hypochromic anaemia, thrombocytopenia, leucopenia, neutrophilia, lymphopenia, monocytosis and eosinophilia were observed following NP exposure together with increase in morphological erythrocyte alterations and micronuclei formation. Elevation in total peroxide and malondialdehyde and depletion in total antioxidant capacity of blood lysate were reported. We concluded that supplementation of NSS markedly ameliorated the previously listed manifestations, and the most effective doses were 25 and 50 g/kg feed.
Research Authors
N.S. Abou Khalil1 | M. Abd-Elkareem2 | A.H. Sayed3
Research Journal
Aquaculture Nutrition
Research Pages
pp. 1-8
Research Publisher
wiley
Research Rank
1
Research Vol
Vol. 1
Research Website
http://onlinelibrary.wiley.com/doi/10.1111/anu.12522/abstract
Research Year
2017

Comments on “Robust circularly orthogonal moment based on Chebyshev rational function” [Digit. Signal Process. 62 (2017) 249–258]

Research Abstract
Comments on the recent work of Guo et al. [1] are presented, in order to correct the erroneous equations. The corrected equations of the Chebychev rational moments, for gray-level images, are presented. In addition, one numerical experiment is performed to ensure the validity of the corrected equations.
Research Authors
Khalid M. Hosny , Mohamed M. Darwish
Research Journal
Digital Signal Processing
Research Pages
PP.152–153
Research Publisher
NULL
Research Rank
1
Research Vol
Vol.68
Research Website
NULL
Research Year
2017

Highly accurate and numerically stable higher order QPCET moments for color image representation

Research Abstract
A novel method is proposed for highly accurate, fast and numerically stable computation of the higher order Quaternion Polar Complex Exponential Transform (QPCET) moments for color images in polar Coordinates. A novel mathematical formula is derived and used to avoid numerical instabilities at higher orders. The proposed method removes the approximation errors involved in conventional methods and provides high image reconstruction capabilities. The proposed method results in a highly accurate rotation invariance. Numerical experiments are performed where the obtained results are compared with those of the recent existing methods.
Research Authors
Khalid M. Hosny , Mohamed M. Darwish
Research Journal
Pattern Recognition Letters
Research Pages
NULL
Research Publisher
NULL
Research Rank
1
Research Vol
NULL
Research Website
NULL
Research Year
2017

Pre-concentration of some heavy metal ions with AlO–HQ and AlO–PHQ and their studies by FTIR and spectroscopy

Research Abstract
Immobilization of HQ and PHQ on the surface of alumina, Al2O3, ( referred to it by AlO ) as an application for cation exchange of Al(III) in solution, used them for extraction of some heavy metal ions from their solutions and calculate the capacity of them. Immobilization of HQ or PHQ on Al2O3 was carried out and used for extraction of some metal ions as Fe(III), Cu(II), Co(II) and Ni(II) from its solution. Spectra of substrate (AlO-HQ, AlO-PHQ or AlO-Cu) at universal buffer solution (pH 7.2 ± 0.1) was recorded, solution of metal ion was added, after contact time, filtrate, and dissolve the solid precipitate in pure ethanol, a peak at 305 nm was observed corresponding to HQ-Al(III). Addition of Cu(II) ion solution to AlO-HQ, a peak at 380 nm was appeared corresponding to HQ-Cu(II), the peak at 305 nm decreased until disappeared . The capacity of AlO-HQ was 100 mmol/g. While, addition of Fe(III) ion solution, new two peaks were appeared at 580 and 455 nm corresponding to formation of HQ-Fe(III) coordinated complex. The capacity of AlO-HQ for Fe(III) ion was 100 mmol/g. In addition of Ni(II) and Co(II) , the capacity of AlO-HQ for extraction of Ni(II) and Co(II) are 62.5 and 150 mmol/g, respectively. In the same conditions, and by the same way, Uv-visible absorption spectra of some metal ions extracted by AlO-PHQ and calculate the capacity of these metals as: [Cu(II): 500, Fe(III): 500, Ni(II): 75 and Co(II): 250 mmol/g ]. As an application, extraction of Ni(II) from real solution sample (Nickel nut) by AlO-PHQ was observed.
Research Authors
Mostafa M. Kamal - Abd El-Aziz Y. El-Sayed - Seddique M. Ahmed -
Ahmed A. Omran - Mohamed M. Shahata
Research Journal
Arabian Journal of Chemistry
Research Pages
8
Research Publisher
Elsevier,
Research Rank
1
Research Vol
(2015) 8, 442-449
Research Website
NULL
Research Year
2015

Cathodic Stripping Defferential pulse Voltammetric Determination of Poly(8-Hydroxyquinoline) Matrix

Research Abstract
ABSTRACT: Cathodic stripping differential pulse voltammetric (CSDPV) procedure was successfully used for the determination of poly(8-roxyquinoline) (PHQ) matrix. The linearity range for the determination of PHQ in the presence (1 mmolL-1) of copper (Cu(II) ion was found to be more sensitive ten times of magnitude higher than the determination of PHQ alone. The lower detection limit was found to be as low as 10 nmolL-1. While, in the case for the determination of Cu(II) ion as a PHQ–Cu(II) chelate, the linearity range is (0 – 4 μmolL-1). The determination of PHQ chain and/or Cu(II) ion was successfully applied in the presence of variety of anions, cations and in an insulating poly(vinyl alcohol) (PVA) matrix. The PVP matrix enhanced the absorbability at the mercury electrode surface which caused increased in the peak high of the chelated Cu(II)
Research Authors
M. M. SHAHATA, S. M. AHMED, M. M. KAMAL
Research Journal
International Journal of Pure & Applied Chemistry,
Research Pages
7
Research Publisher
Global Publishing
Research Rank
1
Research Vol
8 (2013) 218-224.
Research Website
NULL
Research Year
2013

Cationic Mobility Via Cation-Exchange Mechanism on Poly(8-Hydroxyquinoline) Matrix

Research Abstract
The insertion of Al(III) cation into a poly(8- Hydroxyquinoline) (PHQ) instead of some metal ions such as Co(II), Ni(II), Zn(II) or Fe(III) ions via cation-exchange mechanism has been studied by several techniques. The presence of Al(III) and the absence of Co(II) cations has been proved by elemental analysis of the polymer chelates product. Molecular mechanics (MM?) calculations showed that the potential energy (PE, kJ mol-1) of the optimum molecular geometric structure (OMG) of the PHQ–Al(III) matrix is about seventy-six (76.185) greater than the PE of the PHQ–Co(II) complex. The TGA thermograms show that the PHQ–Al(III) matrix is thermally unstable than the PHQ–Co(II) complex under the same conditions. These observations indicate that the PHQ–Al(III) is expanded coil-like form. So, the thermal decomposition of PHQ–Al(III) complex is easy than the compacted coil-likes form of PHQ–Co(II) complex. The incorporation of Al(III) ion via cation-exchange properties have been investigated by spectrophotometric technique. The decrease of the absorbance at about *370 nm of PHQ–Co(II) complex associated with increasing concentration of Al(III) revealed the replacement of that metal ion by Al(III) into PHQ chain. The cation-exchange constant(Kex) of the divalent ions [Ni(II), Co(II), Cr(II), Zn(II), Mn(II), Mg(II) and Cu(II)] from PHQ–M(II) by the additions of Al(III) according to the following series: Ni(II)[Co(II)[Cr(II)[Cu(II)[Zn(II)[Mn(II)[Mg(II).
Research Authors
Mostafa M. Kamal - Abdel-Aziz Y. Al-Sayed - Seddique M. Ahmed - Ahmed E. Omran - Mohamed M. Shahata
Research Journal
J Inorg Organomet Polym
Research Pages
6
Research Publisher
Springer
Research Rank
1
Research Vol
(2009) 19:501-506
Research Website
NULL
Research Year
2009
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