Low temperature synthesis of nano-crystalline h-boron nitride from boric acid/ urea precursors

Dina H.A. Besisa,Mahmoud A. A. Hagras,Emad M.M. Ewais,Yasser M. Z. Ahmed,Zaki I. Zaki,Adel Ahmed 한양대학교 세라믹연구소 2016 Journal of Ceramic Processing Research Vol.17 No.12

Nano-crystalline hexagonal-boron nitride (h-BN) have promised a broad range of interesting applications due to its uniquecharacteristics. In this work, nano-structured h-BN has synthesized by a low temperature-one step reaction of completelydissolved solution of commercial and low cost boric acid and urea fertilizer. Effect of different concentrations of urea, reactionatmosphere (air-N2) and firing temperature (600, 800 oC) on the production of h-BN and type of yield were investigated. Theformation of hexagonal boron nitride was proved from the binding energy for boron and nitrogen obtained from the X- rayphotoelectron spectrum (XPS). The structural phase of the product was confirmed by X-ray diffraction (XRD), Fourier transforminfrared (FT-IR) and differential thermal analysis (DTA). Transmission electron microscopy (HRTEM) has revealed the nanostructure nature of the synthesized boron nitride. The results indicated that, nano-crystalline h-BN with a crystallite size of ≈ 4.5nm has formed at low temperature of 800 oC. Moreover, a good thermal stability and oxidation resistance of h-BN can besynthesized with low cost and at low temperature in the nanoscale and has high potential to be used in advanced applications.

Phytochemical Analysis and Anti-cancer Investigation of Boswellia Serrata Bioactive Constituents In Vitro

Ahmed, Hanaa H,Abd-Rabou, Ahmed A,Hassan, Amal Z,Kotob, Soheir E Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.16

Cancer is a major health obstacle around the world, with hepatocellular carcinoma (HCC) and colorectal cancer (CRC) as major causes of morbidity and mortality. Nowadays, there isgrowing interest in the therapeutic use of natural products for HCC and CRC, owing to the anticancer activity of their bioactive constituents. Boswellia serrata oleo gum resin has long been used in Ayurvedic and traditional Chinese medicine to alleviate a variety of health problems such as inflammatory and arthritic diseases. The current study aimed to identify and explore the in vitro anticancer effect of B. Serrata bioactive constituents on HepG2 and HCT 116 cell lines. Phytochemical analysis of volatile oils of B. Serrata oleo gum resin was carried out using gas chromatography-mass spectrometry (GC/MS). Oleo-gum-resin of B. Serrata was then successively extracted with petroleum ether (extract 1) and methanol (extract 2). Gas-liquid chromatography (GLC) analysis of the lipoidal matter was also performed. In addition, a methanol extract of B. Serrata oleo gum resin was phytochemically studied using column chromatography (CC) and thin layer chromatography (TLC) to obtain four fractions (I, II, III and IV). Sephadex columns were used to isolate ${\beta}$-boswellic acid and identification of the pure compound was done using UV, mass spectra, $^1H$ NMR and $^{13}C$ NMR analysis. Total extracts, fractions and volatile oils of B. Serrata oleo-gum resin were subsequently applied to HCC cells (HepG2 cell line) and CRC cells (HCT 116 cell line) to assess their cytotoxic effects. GLC analysis of the lipoidal matter resulted in identification of tricosane (75.32%) as a major compound with the presence of cholesterol, stigmasterol and ${\beta}$-sitosterol. Twenty two fatty acids were identified of which saturated fatty acids represented 25.6% and unsaturated fatty acids 74.4% of the total saponifiable fraction. GC/MS analysis of three chromatographic fractions (I,II and III) of B. Serrata oleo gum resin revealed the presence of pent-2-ene-1,4-dione, 2-methyl- levulinic acid methyl ester, 3,5- dimethyl- 1-hexane, methyl-1-methylpentadecanoate, 1,1- dimethoxy cyclohexane, 1-methoxy-4-(1-propenyl)benzene and 17a-hydroxy-17a-cyano, preg-4-en-3-one. GC/MS analysis of volatile oils of B. Serrata oleo gum resin revealed the presence of sabinene (19.11%), terpinen-4-ol (14.64%) and terpinyl acetate (13.01%) as major constituents. The anti-cancer effect of two extracts (1 and 2) and four fractions (I, II, III and IV) as well as volatile oils of B. Serrata oleo gum resin on HepG2 and HCT 116 cell lines was investigated using SRB assay. Regarding HepG2 cell line, extracts 1 and 2 elicited the most pronounced cytotoxic activity with $IC_{50}$ values equal 1.58 and $5.82{\mu}g/mL$ at 48 h, respectively which were comparable to doxorubicin with an $IC_{50}$ equal $4.68{\mu}g/mL$ at 48 h. With respect to HCT 116 cells, extracts 1 and 2 exhibited the most obvious cytotoxic effect; with $IC_{50}$ values equal 0.12 and $6.59{\mu}g/mL$ at 48 h, respectively which were comparable to 5-fluorouracil with an $IC_{50}$ equal $3.43{\mu}g/mL$ at 48 h. In conclusion, total extracts, fractions and volatile oils of B. Serrata oleo gum resin proved their usefulness as cytotoxic mediators against HepG2 and HCT 116 cell lines with different potentiality (extracts > fractions > volatile oil). In the two studied cell lines the cytotoxic acivity of each of extract 1 and 2 was comparable to doxorubicin and 5-fluorouracil, respectively. Extensive in vivo research is warranted to explore the precise molecular mechanisms of these bioactive natural products in cytotoxicity against HCC and CRC cells.

Allelic variation of melanocortin-1 receptor locus in Saudi indigenous sheep exhibiting different color coats

Mahmoud, Ahmed H.,Mashaly, Ashraf M.,Rady, Ahmed M.,Al-Anazi, Khalid M.,Saleh, Amgad A. Asian Australasian Association of Animal Productio 2017 Animal Bioscience Vol.30 No.2

Objective: This study was designed to characterize the DNA polymorphisms of the melanocortin-1 receptor (MC1R) gene in indigenous Saudi Arabian sheep breeds exhibiting different color coats, along with individuals of the Sawaknee breed, an exotic sheep imported from Sudan. Methods: The complete coding region of MC1R gene including parts of 3' and 5' untranslated regions was amplified and sequenced from three the indigenous Saudi sheep; Najdi (generally black, n = 41), Naeimi (generally white with brown faces, n = 36) and Herri (generally white, n = 18), in addition to 13 Sawaknee sheep. Results: Five single nucleotide polymorphisms (SNPs) were detected in the MC1R gene: two led to nonsynonymous mutations (c.218 T>A, p.73 Met>Lys and c.361 G>A, p.121 Asp>Asn) and three led to synonymous mutations (c.429 C>T, p.143 Tyr>Tyr; c.600 T>G, p.200 Leu>Leu, and c.735 C>T, p.245 Ile>Ile). Based on these five SNPs, eight haplotypes representing MC1R $E^d$ and $E^+$ alleles were identified among the studied sheep breeds. The most common haplotype (H3) of the dominant $E^d$ allele was associated with either black or brown coat color in Najdi and Sawaknee sheep, respectively. Two other haplotypes (H6 and H7) of $E^d$ allele, with only the nonsynonymous mutation A218T, were detected for the first time in Saudi indigenous sheep. Conclusion: In addition to investigating the MC1R allelic variation in Saudi indigenous sheep populations, the present study supports the assumption that the two independent nonsynonymous Met73Lys and Asp121Asn mutations in MC1R gene are associated with black or red coat colors in sheep breeds.

Original Article : Treatment for Eradication of Helicobacter pylori Infection among Chronic Hepatitis C Patients

( Norihiro Furusyo ),( Ahmed H. Walaa ),( Kunimitsu Eiraku ),( Kazuhiro Toyoda ),( Eiichi Ogawa ),( Hiroaki Ikezaki ),( Takeshi Ihara ),( Takeo Hayashi ),( Mosaburo Kainuma ),( Masayuki Murata ),( Jun 대한간학회 2011 Gut and Liver Vol.5 No.4

Background/Aims: Helicobacter pylori infection causes gastritis, peptic ulcers and gastric malignancies, and its eradication has been advocated by many groups. We determined the H. pylori carrier status and eradication rates of patients with chronic hepatitis C virus (HCV) infection. Methods: In total, 76 chronically HCV-infected patients were enrolled for comparison with 228 HCV-noninfected, age- and sex-matched controls. H. pylori infection was confirmed by H. pylori antibody and urea breath testing. Results: The H. pylori infection rate was significantly higher for HCV-infected patients (67 of 76, 88.2%) than for HCV-noninfected controls (158 of 228, 69.3%). Endoscopic fi ndings showed that the rates of gastric ulcers and gastritis were significantly higher for the 67 HCV-infected patients with H. pylori infection (34.3% and 77.6%) than for the 158 HCV-noninfected controls with H. pylori infection (15.2% and 57.6%). Treatment to eradicate H. pylori had a signifi cantly higher success rate for HCV-infected patients (61 of 67, 91.0%) than for HCV-noninfected controls (115 of 158, 72.8%). Conclusions: The markedly high H. pylori eradication rate observed in this study shows that eradication of H. pylori holds promise for the improvement of the long-term health condition of patients with chronic HCV infection. (Gut Liver 2011;5:447-453)

Efficacy of Nile tilapia (Oreochromis niloticus) juveniles and spinosyns bioinsecticides against aquatic stages of Culex pipiens: An experimental study

Mohamed Ibrahim A.,Fathy Mohamed,Farghal Ahmed I.A.,Temerak Sobhy A.H.,Sayed Alaa El-Din H. 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.1

The mosquito Culex pipiens is the most widely distributed dipteran species in all regions of Egypt and the principal vector of Wuchereria bancrofti and certain arboviruses in human beings. For controlling C. pipiens vector, biological tools (e.g., larvivorous fish and bioinsecticides) are more potent and safer options to the environment, human beings, and beneficial organisms than chemical pesticides. The efficiency of O. niloticus juveniles as predatory fish species and two bioinsecticides, spinosad 24% and spinetoram 12%, was investigated against the C. pipiens developmental stages in the laboratory. The first trial evaluated the predatory efficacy of small-sized O. niloticus (2.1–2.6 cm; 250–315 mg) and large-sized O. niloticus (2.5–3.2 cm; 250–315 mg) against the 3rd larvae and pupae of C. pipiens. This is the first report in Egypt confirming the predation potential of O. niloticus as efficient predatory fish against the immature C. pipiens. Large-sized O. niloticus predated a greater number of 3rd of C. pipiens larvae and pupae than the small-sized ones. Furthermore, the daily consumption of C. pipiens larvae by small- and large-sized O. niloticus was significantly higher than the pupae. The second trial assessed the toxicity efficacy of spinosad 24% and spinetoram 12% against C. pipiens larvae and pupae. The results confirmed that the tested bioinsecticides showed higher potency toward C. pipiens larvae than pupae after exposure for 24 h and 48 h. Spinosad was more toxic toward 3rd C. pipiens larvae (LC 50 = 0.013 and 0.003 mg/L) and pupae (LC 50 = 320.69 and 44.28 mg/L) than spinetoram after 24 and 48 h. Herein, O. niloticus juveniles (as promising native predatory fish) and spinosyns bioinsecticides were more effective against C. pipiens in the larval stage than in the pupal stage. In conclusion, Nile tilapia juveniles and biorational compounds, spinosad 24% and spinetoram 12%, might be considered as promising and favorable environmental biological agents for controlling C. pipiens in Egypt. However, further trials are needed to investigate the potential of these agents in the control of this mosquito vector under field conditions.

Comparison of the Hospital-Acquired Clostridium difficile Infection Risk of Using Proton Pump Inhibitors versus Histamine-2 Receptor Antagonists for Prophylaxis and Treatment of Stress Ulcers: A Systematic Review and Meta-Analysis

( Mohamed Azab ),( Loomee Doo ),( Daniel H. Doo ),( Yousif Elmofti ),( Muazer Ahmed ),( John Jay Cadavona ),( Xibei B. Liu ),( Amaan Shafi ),( Moon Kyung Joo ),( Ji Won Yoo ) 대한간학회 2017 Gut and Liver Vol.11 No.6

Background/Aims: Although proton pump inhibitors (PPIs) have been widely used for the prevention and treatment of stress gastric ulcers in hospital settings, there are concerns that PPIs increase the risk of Clostridium difficile infection (CDI). However, little is known about the risk of CDI following PPI and histamine-2 receptor antagonist (H2RA) use. We evaluated the comparative hospital-acquired CDI occurrence risk associated with the concurrent use of PPIs versus H2RAs. Methods: A systematic search of PubMed, MEDLINE/Ovid, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science, and Google Scholar through August 19, 2016, identified 12 studies that reported the hospital-acquired CDI occurrence following H2RA and PPI use for the prevention and treatment of stress gastric ulcers. Random-effects pooled odds ratios and 95% confidence intervals were estimated. Heterogeneity was measured using I2, and a meta-regression analysis was conducted. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system was used to assess the overall quality of the evidence. Results: A total of 74,132 patients from 12 observational studies were analyzed. Compared to H2RAs, PPIs increased the risk of CDI by 38.6% (pooled odds ratio, 1.386; 95% confidence interval, 1.152 to 1.668; p=0.001; I2=42.81%). Subgroup analyses of the purpose of study medication use, study site, and study design confirmed the consistency of a greater CDI risk with PPIs than with H2RAs. The overall quality of evidence was rated as low. Conclusions: The use of PPIs for both the prevention and treatment of stress ulcers was associated with a 38.6% increased risk of hospital-acquired CDI occurrence compared to H2RA use. (Gut Liver 2017;11:781-788)

Numerical desirability function for adsorption of methylene blue dye by sulfonated pomegranate peel biochar: Modeling, kinetic, isotherm, thermodynamic, and mechanism study

Ali H. Jawad,Ahmed Saud Abdulhameed,M. A. K. M. Hanafiah,Zeid A. AlOthman,Mohammad Rizwan Khan,S. N. Surip 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.7

Sulfonated pomegranate (Punica granatum) peel biochar (SPPBC) was developed via thermal activation with sulfuric acid (H2SO4) to act as a promising biochar material for the adsorptive removal of toxic cationic dye namely methylene blue (MB) dye from contaminated water. A Box-Behnken design (BBD) and numerical desirability function were adopted to optimize the input adsorption variables (SPPBC dosage, temperature, pH, and contact time). The maximum removal of the MB dye can be accomplished by simultaneous significant interaction between SPPBC dosage with solution pH, SPPBC dosage with time, SPPBC dosage with temperature, solution pH with time, and time with temperature. The numerical desirability function identified the highest MB dye removal (93.9%) can be achieved at the following optimum numerical adsorption conditions: SPPBC dosage 0.18 g, temperature 49 oC, pH 9.7, and time 4.3 h. Equilibrium data were well fitted to the Temkin and Langmuir isotherm models. The maximum recorded adsorption capacity of SPPBC for MB dye adsorption by using Langmuir isotherm model was 161.9mg/g. This research work reveals the possibility of converting lignocellulose pomegranate peel into a renewable and environmentfriendly biochar via a relatively fast acid-activation process with the great potential to be promising adsorbent for removal of MB dye.

Sensitivity and Uncertainty quantification of neutronic integral data in the TRIGA Mark II Research Reactor

M. Makhloul,H. Boukhal,E. Chakir,T. El Bardouni,M. Lahdour,M. Kaddour,Abdulaziz Ahmed,A. Arectout,H. El Yaakoubi 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.2

In order to study the sensitivity and the uncertainty of the Moroccan research reactor TRIGA Mark II, amodel of this reactor has been developed in our ERSN laboratory for use with the N-Particle MCNP MonteCarlo transport codes (version 6). In this article, the sensitivities of the effective multiplication factor ofthis reactor are evaluated using the ENDF/B-VII.0, ENDF/B-VII.1 and JENDL-4.0 libraries and in 44 energygroups, for the cross sections of the fuel (U-235 and U-238) and the moderator (H-1 and O-16). However,the quantification of the uncertainty of the nuclear data is performed using the nuclear code NJOY99 forthe generation and processing of covariance matrices. On the one hand, the highest uncertainty deviations, calculated using the ENDFB-VII.1 and JENDL4.0 evaluations, are 2275, 386 and 330 pcmrespectively for the reactions U235(n, f), U235(nn) and H1(n, g). On the other hand, these differences arevery small for the neutron reactions of O-16 and U-238. Regarding the neutron spectra, in CT-mid plane,they are very close for the three evaluations (ENDF/B-VII.0, ENDF/B-VII.1 and JENDL-4.0). These spectrapresent two peaks (thermal and fission) around the energies 0.05 eV and 1 MeV

Performance Enhancement for a Class of Hysteresis Nonlinearities using Disturbance Observers

Mohammad Al Janaideh,Ahmed H. El-Shaer 제어·로봇·시스템학회 2014 International Journal of Control, Automation, and Vol.12 No.2

This paper addresses performance enhancement using disturbance observers (DOBs) for a class of hysteresis nonlinearities characterized by the Prandtl-Ishlinskii model. The proposed approach makes use of internal model-based estimation of exogenous disturbances. The synthesis of the DOB is formulated as an H∞ weighted-sensitivity optimization for static output feedback (SOF) gain of a Luenberger observer. A linearization approach is then implemented to solve the rank-constrained (non-convex) constrained semi-definite program (SDP) for the (sub) optimal static gain. Simulation results indicate that the closed-loop tracking performance is indeed enhanced using the DOB for reference in-puts at different excitation frequencies.

Measurement of cos2β in B0→D(*)h0 with D→KS0π+π− decays by a combined time-dependent Dalitz plot analysis of <i>BaBar</i> and Belle data

Adachi, I.,Adye, T.,Ahmed, H.,Ahn, J. K.,Aihara, H.,Akar, S.,Alam, M. S.,Albert, J.,Anulli, F.,Arnaud, N.,Asner, D. M.,Aston, D.,Atmacan, H.,Aushev, T.,Ayad, R.,Badhrees, I.,Bakich, A. M.,Banerjee, Sw American Physical Society 2018 Physical Review D Vol.98 No.11