Purification and Characterization of Anabaena flos-aquae Phenylalanine Ammonia-Lyase as a Novel Approach for Myristicin Biotransformation

Asmaa M. Arafa,Afaf E. Abdel-Ghany,Samih I. El-Dahmy,Sahar Abdelaziz,Yassin El-Ayouty,Ashraf S. A. El-Sayed 한국미생물·생명공학회 2020 Journal of microbiology and biotechnology Vol.30 No.4

Phenylalanine ammonia-lyase (PAL) catalyzes the reversible deamination of phenylalanine to cinnamic acid and ammonia. Algae have been considered as biofactories for PAL production, however, biochemical characterization of PAL and its potency for myristicin biotransformation into MMDA (3-methoxy-4, 5-methylenedioxyamphetamine) has not been studied yet. Thus, PAL from Anabaena flos-aquae and Spirulina platensis has been purified, comparatively characterized and its affinity to transform myristicin was assessed. The specific activity of purified PAL from S. platensis (73.9 μmol/mg/min) and A. flos-aquae (30.5 μmol/mg/min) was increased by about 2.9 and 2.4 folds by gel-filtration comparing to their corresponding crude enzymes. Under denaturing-PAGE, a single proteineous band with a molecular mass of 64 kDa appeared for A. flos-aquae and S. platensis PAL. The biochemical properties of the purified PAL from both algal isolates were determined comparatively. The optimum temperature of S. platensis and A. flos-aquae PAL for forward or reverse activity was reported at 30oC, while the optimum pH for PAL enzyme isolated from A. flos-aquae was 8.9 for forward and reverse activities, and S. platensis PAL had maximum activities at pH 8.9 and 8 for forward and reverse reactions, respectively. Luckily, the purified PALs have the affinity to hydroaminate the myristicin to MMDA successfully in one step. Furthermore, a successful method for synthesis of MMDA from myristicin in two steps was also established. Gas chromatography-mass spectrometry (GC-MS) analysis was conducted to track the product formation.

A novel morphology of 3D graphene hydrogel nanotubes for high-performance nonenzymatic hydrogen peroxide sensor

Mohamed A. Yassin,Bishnu Kumar Shrestha,Joshua Lee,김주연,박찬희,김철상 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.79 No.-

A novel nanostructure of three-dimensional graphene hydrogel nanotubes (3DGHNTs) is successfullysynthesized for the purpose of sensing non-enzymatic H2O2 in alkaline solution. The 3DGHNTs werefabricated using manganese dioxide nanotubes (MnO2 NTs) as the effective sacrificial template andwithout the use of any acids or a high temperature process. 3DGH with different percentages of MnO2NTs ranging from 5 to 30% are prepared via a hydrothermal method. When the loading percentage ofMnO2 NTs is 10%, the obtained 3DGHNTs-Mn10 nanocomposite exhibits a large specific surface areawith high porosity, which enhance the electrochemical properties for H2O2 detection. The developedbiosensor exhibits excellent sensitivity (220.4 mA mM 1 cm 2) with a wide linear detection range (25 mM–22.57 mM) and a low detection limit (4 mM). The biosensor also shows a fast response time (lessthan 5 s) and good selectivity as well as reproducibility and long-term stability. Hence, the prepared3DGHNTs-Mn10 nanocomposite can be considered a promising electrode material for the detection ofH2O2 in real sample.

Exfoliated nanosheets of Co3O4 webbed with polyaniline nanofibers: A novel composite electrode material for enzymeless glucose sensing application

Mohamed A. Yassin,Bishnu Kumar Shrestha,Rafiq Ahmad,Sita Shrestha,박찬희,김철상 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.73 No.-

A novel glucose biosensor was designed using cobalt oxide (Co3O4) nanosheets patterned byp-conjugated polyaniline nanofibers (PANINFs). A facile synthesis process was conducted to obtaincost-effective and ecofriendly mesoporous Co3O4@PANINFs hybrid nanomaterial for thefirst time. TheCo3O4@PANINFs on glassy carbon electrode (GCE), working as a biosensor electrode based onelectrochemical technique, showed electrocatalytic activity to glucose with sensitivity of 14.25 mAmM 1cm 2, linear range from (0.1 to 8) mM, minimum detection limit of 0.06 mM, and response time<6 s. Moreover, the biosensor was employed to monitor glucose concentration in human serum sample toprovide effective sensing results.

Nanoparticles of ZnO/Berberine complex contract COVID-19 and respiratory co-bacterial infection in addition to elimination of hydroxychloroquine toxicity

Ghareeb Doaa A.,Saleh Samar R.,Seadawy Mohamed G.,Nofal Mohammed S.,Abdulmalek Shaymaa A.,Hassan Salma. F.,Khedr Shaimaa M.,AbdElwahab Miral G.,Sobhy Ahmed A.,Abdel-Hamid Ali saber Ali,Yassin Abdelrah 한국약제학회 2021 Journal of Pharmaceutical Investigation Vol.51 No.6

Purpose A novel coronavirus (COVID-19) that has not been previously identified in humans and has no specific treatment has recently spread. Treatment trials using antiviral and immune-modulating drugs such as hydroxychloroquine (HCQ) were used to control this viral outbreak however several side effects have emerged. Berberine (BER) is an alkaloid that has been reported to reveal some pharmacological properties including antioxidant and antimicrobial activities. Additionally, Zinc oxide nanoparticles (ZnO-NPs) possess potent antioxidant and anti-inflammatory properties. Therefore, this study was undertaken to estimate the efficiency of both BER and synthetic ZnO/BER complex as an anti-COVID-19 therapy. Methods First, the ZnO/BER complex was prepared by the facile mixing method. Then in vitro studies on the two compounds were conducted including VeroE6 toxicity, anti-COVID-19 activity, determination of inhibitory activity towards papain-like proteinase (PL pro) and spike protein- and receptor- binding domain (RBD) as well as assessment of drug toxicity on RBCs. Results The results showed that ZnO/BER complex acts as an anti-COVID-19 by inhibiting spike protein binding with angiotensin-converting enzyme II (ACE II), PL pro activity, spike protein and E protein levels, and expression of both E-gene and RNA dependent RNA polymerase (RdRp) at a concentration lower than that of BER or ZnO-NPs alone. Furthermore, ZnO/BER complex had antioxidant and antimicrobial properties where it prevents the auto oxidation of 2,2-Diphenyl- 1-picrylhydrazyl (DPPH) and the culture of lower respiratory system bacteria that affected Covid 19 patients. The ZnO/BER complex prevented as well the HCQ cytotoxic effect on both RBC and WBC (in vitro) and hepatotoxicity, nephrotoxicity and anemia that occurred after HCQ long administration in vivo. Conclusion The ZnO/BER complex can be accounted as promising anti-COVID 19 candidate because it inhibited the virus entry, replication, and assembly. Furthermore, it could be used to treat a second bacterial infection that took place in hospitalized COVID 19 patients. Moreover, ZnO/BER complex was found to eliminate the toxicity of long-term administration of HCQ in vivo.

INVESTIGATION OF DRAG REDUCTION MECHANISM BY MICROBUBBLE INJECTION WITHIN A CHANNEL BOUNDARY LAYER USING PARTICLE TRACKING VELOCIMETRY

Hassan Yassin A.,Gutierrez-Torres C.C. Korean Nuclear Society 2006 Nuclear Engineering and Technology Vol.38 No.8

Injection of microbubbles within the turbulent boundary layer has been investigated for several years as a method to achieve drag reduction. However, the physical mechanism of this phenomenon is not yet fully understood. Experiments in a channel flow for single phase (water) and two phase (water and microbubbles) flows with various void fraction values are studied for a Reynolds number of 5128 based on the half height of the channel and bulk velocity. The state-of-the art Particle Tracking Velocimetry (PTV) measurement technique is used to measure the instantaneous full-field velocity components. Comparisons between turbulent statistical quantities with various values of local void fraction are presented to elucidate the influence of the microbubbles presence within the boundary layer. A decrease in the Reynolds stress distribution and turbulence production is obtained with the increase of microbubble concentration. The results obtained indicate a decorrelation of the streamwise and normal fluctuating velocities when microbubbles are injected within the boundary layer.

Synthesis of 4, 5, 6, 7-Tetraphenyl-8-(substituted)-3 (2H)-phthalazinone Derivatives Likely to Posses Antihypertensive Activity

F.A. Yassin,B.E. Bayoumy,A.F. El-Farargy Korean Chemical Society 1990 Bulletin of the Korean Chemical Society Vol.11 No.1

The interaction of tetraphenylphthalic anhydride with o-chlorotoluene under Friedel-Craft condition gives 2-(4-chloro-3-methyl)benzoyl-3,4,5,6-tetraphenyl benzoic acid(1), which on reaction with hydrazine derivatives gave phthalazinones (2a-d). The behaviour of (2a) towards carbon electrophiles and carbon nucleophiles has been investigated. The chlorophthalazinones (4a) also has been synthesized from the action of $PCl_5/POCl_3$ on (2a). The behaviour of (4a) towards nitrogen, and oxygen nucleophiles also have been described.

Determinants of the willingness of the general population to get vaccinated against COVID-19 in a developing country

Abdel-Hameed Al-Mistarehi,Khalid A. Kheirallah,Ahmed Yassin,Safwan Alomari,Maryam K. Aledrisi,Ehab M. Bani Ata,Nouran H. Hammad,Asim N. Khanfar,Ali M. Ibnian,Basheer Y. Khassawneh 대한백신학회 2021 Clinical and Experimental Vaccine Research Vol.10 No.2

Purpose: Vaccination is a cost-efficient intervention to slow the spread of the coronavirus disease 2019 (COVID-19) pandemic. This study aims to assess the population’s willingness to take the COVID-19 vaccine in Jordan and investigate potential determinants of their acceptance. Materials and Methods: This study used an online survey distributed in November 2020, before introducing the vaccine, with items investigating socio-demographic characteristics, seasonal flu vaccination history, COVID-19 vaccine acceptance once available, and factors affecting their decision-making. Also, “COVID-19 risk perception” and beliefs toward COVID-19 vaccine benefits and barriers were assessed. Results: A total of 2,208 participants completed the survey with a participation rate of 13.1%. The mean±standard deviation age was 33.2±13.5, and 55.7% were females. Study participants were almost equally distributed between willingness, unwillingness, and indecision to take the COVID-19 vaccine (30.4%, 36.4%, and 31.5%, respectively). Younger adults, males, and those who were not married, do not have children, have a bachelor or higher education, employees or being students, healthcare workers, and those who reported receiving flu vaccine had higher rates of COVID-19 vaccine acceptance compared to their counterparts (p<0.001 for each category). COVID-19 risk perception, and perceived vaccine benefits, and barriers were significant predictors of intention. Among those undecided or unwilling to take the COVID-19 vaccine, its safety and side effects were the most common concerns. Conclusion: The low rate of COVID-19 vaccine acceptance in a developing country is alarming, and a significant proportion are indecisive. Interventions to elevate vaccine acceptance by addressing its safety and efficacy and targeting vulnerable groups are recommended.

Optimal sensor placement for mode shapes using improved simulated annealing

K.H. Tong,Norhisham Bakhary,A.B.H. Kueh,A.Y. Mohd Yassin 국제구조공학회 2014 Smart Structures and Systems, An International Jou Vol.13 No.3

Optimal sensor placement techniques play a significant role in enhancing the quality of modal data during the vibration based health monitoring of civil structures, where many degrees of freedom are available despite a limited number of sensors. The literature has shown a shift in the trends for solving such problems, from expansion or elimination approach to the employment of heuristic algorithms. Although these heuristic algorithms are capable of providing a global optimal solution, their greatest drawback is the requirement of high computational effort. Because a highly efficient optimisation method is crucial for better accuracy and wider use, this paper presents an improved simulated annealing (SA) algorithm to solve the sensor placement problem. The algorithm is developed based on the sensor locations‟ coordinate system to allow for the searching in additional dimensions and to increase SA‟s random search performance while minimising the computation efforts. The proposed method is tested on a numerical slab model that consists of two hundred sensor location candidates using three types of objective functions; the determinant of the Fisher information matrix (FIM), modal assurance criterion (MAC), and mean square error (MSE) of mode shapes. Detailed study on the effects of the sensor numbers and cooling factors on the performance of the algorithm are also investigated. The results indicate that the proposed method outperforms conventional SA and Genetic Algorithm (GA) in the search for optimal sensor placement.

Optimal sensor placement for mode shapes using improved simulated annealing

Tong, K.H.,Bakhary, Norhisham,Kueh, A.B.H.,Yassin, A.Y. Mohd Techno-Press 2014 Smart Structures and Systems, An International Jou Vol.13 No.3

Optimal sensor placement techniques play a significant role in enhancing the quality of modal data during the vibration based health monitoring of civil structures, where many degrees of freedom are available despite a limited number of sensors. The literature has shown a shift in the trends for solving such problems, from expansion or elimination approach to the employment of heuristic algorithms. Although these heuristic algorithms are capable of providing a global optimal solution, their greatest drawback is the requirement of high computational effort. Because a highly efficient optimisation method is crucial for better accuracy and wider use, this paper presents an improved simulated annealing (SA) algorithm to solve the sensor placement problem. The algorithm is developed based on the sensor locations' coordinate system to allow for the searching in additional dimensions and to increase SA's random search performance while minimising the computation efforts. The proposed method is tested on a numerical slab model that consists of two hundred sensor location candidates using three types of objective functions; the determinant of the Fisher information matrix (FIM), modal assurance criterion (MAC), and mean square error (MSE) of mode shapes. Detailed study on the effects of the sensor numbers and cooling factors on the performance of the algorithm are also investigated. The results indicate that the proposed method outperforms conventional SA and Genetic Algorithm (GA) in the search for optimal sensor placement.

Novel 4-(4-substituted-thiazol-2-ylamino)-N-(pyridin-2-yl)-benzenesulfonamides as Cytotoxic and Radiosensitizing Agents

Mostafa M. Ghorab,Fatma A. Ragab,Helmy I. Heiba,Hebaallah M. Agha,Yassin M. Nissan 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.1

A series of novel 4-(4-substituted-thiazol-2-ylamino)-N-(pyridin-2-yl) benzene-sulfonamides were synthesized and screened for their cytotoxic activity against human breast cancer cell line (MCF-7). Compounds 6, 7, 9, 10, 11, and 14 displayed significant activity against MCF-7 when compared to doxorubicin, which was used as a reference drug. The synergistic effect of Gamma radiation for the most active derivatives 7, 9, and 11 was also studied and their IC50 values markedly decreased to 11.9 μM, 11.7 μM, and 11.6 μM, respectively.