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Search Results: 1 - 10 of 314979 matches for " F. D. Muhammad "
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Thermal Stability and Effect of Heat Treatment on Manganese Doped Silica Borotellurite Glass  [PDF]
I. Zaitizila, M. K. Halimah, F. D. Muhammad, M. F. Faznny
Journal of Materials Science and Chemical Engineering (MSCE) , 2018, DOI: 10.4236/msce.2018.64004
Abstract:
Glasses with chemical formula of {[(TeO2)0.7(B2O3)0.3]0.8[SiO2]0.2}1-x{MnO2}x where x = 0.00 ≤ x ≤ 0.05 molar fraction were fabricated using melt quenching technique. The temperature used in the heat treatment process of the glass sample is 600?C. Calorimetric measurement had been carried out to study the thermal properties of the fabricated glass. The crystallization kinetics of the glass system we reexamined under non-isothermal conditions via differential scanning calorimetric (DSC). The glass transition (Tg), onset glass transition (To), maximum crystallization temperature (Tc) and melting temperature (Tm) were determined. Results from DSC proved that the studied glasses have good thermal stability (Ts) in which indicates its high resistance to devitrification. Strong indicator for the glass forming ability of a glass material, Hurby parameter (Kgl) was also calculated in this research.
On $v$--domains and star operations
D. D. Anderson,David F. Anderson,Marco Fontana,Muhammad Zafrullah
Mathematics , 2008,
Abstract: Let $\ast$ be a star operation on an integral domain $D$. Let $\f(D)$ be the set of all nonzero finitely generated fractional ideals of $D$. Call $D$ a $\ast$--Pr\"ufer (respectively, $(\ast, v)$--Pr\"ufer) domain if $(FF^{-1})^{\ast}=D$ (respectively, $(F^vF^{-1})^{\ast}=D$) for all $F\in \f(D)$. We establish that $\ast$--Pr\"ufer domains (and $(\ast, v)$--Pr\"ufer domains) for various star operations $\ast $ span a major portion of the known generalizations of Pr\"{u}fer domains inside the class of $v$--domains. We also use Theorem 6.6 of the Larsen and McCarthy book [Multiplicative Theory of Ideals, Academic Press, New York--London, 1971], which gives several equivalent conditions for an integral domain to be a Pr\"ufer domain, as a model, and we show which statements of that theorem on Pr\"ufer domains can be generalized in a natural way and proved for $\ast$--Pr\"ufer domains, and which cannot be. We also show that in a $\ast $--Pr\"ufer domain, each pair of $\ast $-invertible $\ast $-ideals admits a GCD in the set of $\ast $-invertible $\ast $-ideals, obtaining a remarkable generalization of a property holding for the "classical" class of Pr\"ufer $v$--multiplication domains. We also link $D$ being $\ast $--Pr\"ufer (or $(\ast, v)$--Pr\"ufer) with the group Inv$^{\ast}(D)$ of $\ast $-invertible $\ast $-ideals (under $\ast$-multiplication) being lattice-ordered.
Enhanced Dissolution and Oral Bioavailability of Piroxicam Formulations: Modulating Effect of Phospholipids
Sabiruddin Mirza,Inna Miroshnyk,Muhammad J. Habib,James F. Brausch,Muhammad D. Hussain
Pharmaceutics , 2010, DOI: 10.3390/pharmaceutics2040339
Abstract: Several biologically relevant phospholipids were assessed as potential carriers/additives for rapidly dissolving solid formulations of piroxicam (Biopharmaceutics Classification System Class II drug). On the basis of in vitro dissolution studies, dimyristoylphosphatidylglycerol (DMPG) was ranked as the first potent dissolution rate enhancer for the model drug. Subsequently, the solid dispersions of varying piroxicam/DMPG ratios were prepared and further investigated. Within the concentration range studied (6.4-16.7 wt %), the dissolution rate of piroxicam from the solid dispersions appeared to increase as a function of the carrier weight fraction, whereas the cumulative drug concentration was not significantly affected by piroxicam/DMPG ratio, presumably due to a unique phase behavior of the aqueous dispersions of this carrier phospholipid. Solid state analysis of DMPG-based formulations reveled that they are two-component systems, with a less thermodynamically stable form of piroxicam (Form II) being dispersed within the carrier. Finally, oral bioavailability of piroxicam from the DMPG-based formulations in rats was found to be superior to that of the control, as indicated by the bioavailability parameters, c max and especially T max (53 μg/mL within 2 h vs. 39 μg/mL within 5.5 h, respectively). Hence, DMPG was regarded as the most promising carrier phospholipid for enhancing oral bioavailability of piroxicam and potentially other Class II drugs.
Lipid Peroxidation and Some Antioxidant Enzymes Evaluation in Apple Cider Vinegar (ACV) Treated Male and Female Wistar Rats Exposed to Chronic Restraint Stress  [PDF]
R. A. Abdulrauf, F. A. Dawud, N. S. Emmanuel, H. D. Muhammad, A. S. Dange, B. A. David, A. E. Ogweje, A. U. Alexander, M. Yahuza
Advances in Enzyme Research (AER) , 2018, DOI: 10.4236/aer.2018.63003
Abstract: This study was designed to assess the effect to apple cider vinegar (ACV) on oxidative stress biomarkers in male and female Wistar rats exposed to chronic restraint stress. Severe and persistent stress elevates reactive oxygen species (ROS) production by metabolic and physiological processes; causing cellular damage. Thirty (30) Adult Wistar rats of both sexes weighing about 150 - 200 g were divided into 3 groups each consisting of a male and female subgroup and given the following treatments once a day for 21 days: Normal control group received 0.5 ml distilled water orally, the restraint stress (RS) group was exposed to chronic restraint stress 6 hours daily while the Apple cider vinegar (ACV)-treated group received 4 ml/kg of apple cider vinegar orally in addition to chronic restraint stress 6 hours daily. The rats were sacrificed after the experimental period and blood was collected via cardiac puncture for assessing oxidative stress biomarkers. ACV (4 ml/kg) treatment decreased lipid peroxidation (MDA) and serum catalase (CAT) activity while upregulating endogenous superoxide dismutase (SOD) activity. The findings of this study show that the female Wistar rats are more predisposed to the antioxidant effect of ACV than the males.
Extracting the Atomic Coordinates and Connectivity of Zirconia Nanotubes from PDB Files for Modelling in ANSYS  [PDF]
Ibrahim D. Muhammad, Mokhtar Awang
Advances in Nanoparticles (ANP) , 2014, DOI: 10.4236/anp.2014.33013
Abstract:
Zirconia in the form of nanotubes has potential for application in various areas. However, information on structural and mechanical properties of zirconia nanotubes is not easily available and/ or limited in scope. This challenge requires multi-scale numerical modeling and simulation. As a way out, the structure of (10, 10) zirconia nanotube is modeled using available crystal and molecular software (Material Studio© and CrystalMaker©). The output in the form of PDB file is exported into ANSYS by using a script developed in Python. The output contains only the atomic coordinates and connectivity pattern, which make the conversion process faster and more efficient compared to manual option used when performing similar task.
Dynamics of the Markov Time Scale of Seismic Activity May Provide a Short-Term Alert for Earthquakes
M. Reza Rahimi Tabar,Muhammad Sahimi,K. Kaviani,M. Allamehzadeh,J. Peinke,M. Mokhtari,M. Vesaghi,M. D. Niry,F. Ghasemi,A. Bahraminasab,S. Tabatabai,F. Fayazbakhsh
Physics , 2005,
Abstract: We propose a novel method for analyzing precursory seismic data before an earthquake that treats them as a Markov process and distinguishes the background noise from real fluctuations due to an earthquake. A short time (on the order of several hours) before an earthquake the Markov time scale $t_M$ increases sharply, hence providing an alarm for an impending earthquake. To distinguish a false alarm from a reliable one, we compute a second quantity, $T_1$, based on the concept of extended self-similarity of the data. $T_1$ also changes strongly before an earthquake occurs. An alarm is accepted if {\it both} $t_M$ and $T_1$ indicate it {\it simultaneously}. Calibrating the method with the data for one region provides a tool for predicting an impending earthquake within that region. Our analysis of the data for a large number of earthquakes indicate an essentially zero rate of failure for the method.
Genetic Transformation Studies on Avocado Cultivar “Hass” (Persea americana)  [PDF]
Muhammad F. Ahmed, Arumugam S. Kantharajah, Paul Holford
American Journal of Plant Sciences (AJPS) , 2012, DOI: 10.4236/ajps.2012.39148
Abstract: The use of traditional breeding for improvement of avocado cultivars is time consuming, hence other methods such as genetic transformation by Agrobacterium is indispensable to adopt. The strain GV3850/pBI121gave best transformation outcome compared to five other binary vectors (AGL1/pCGP904; AGL1/pBI121; GV3850/pCGP904; LBA4404/pCG-P904 and LBA4404/pBI121) under different pH and acetosyringone concentrations. The optimal condition for reliable transformation was by using 200 μM acetosyringone and a pH of 5.2. Transformed embryonic shoots co-cultivated with GV3850/pBI121 were tested using the histochemical x-gluc assay. Further analysis was conducted by polymerase chain reaction using specific primers for the reporter gene (GUS).
A Finite Element Analysis Study Comparing 3 Internal Fixation Techniques in Mandibular Sagittal Split Osteotomy  [PDF]
Muhammad Kamil Hassan, Michael Ring, Leo F. A. Stassen
International Journal of Otolaryngology and Head & Neck Surgery (IJOHNS) , 2018, DOI: 10.4236/ijohns.2018.75030
Abstract: Purpose: To analyse, and compare using finite element analysis, the biomechanical properties of the 1.7 mm miniplate fixation against 2 conventional fixation techniques (2.0 mm bi-cortical screws and 2.0 mm miniplate) used in the mandibular sagittal split osteotomy. Methods: A 3-D virtual mandible model was constructed using images from CT scan. Sagittal split osteotomy was carried out virtually, and the fixation techniques were applied onto the model. 9 virtual models consisted of the 3 fixation techniques with mandibular movements of 3 mm setback, 3 mm advancement and 7 mm advancement were developed. Bite forces of 50, 75 and 100 N were applied for incisor bite simulation and 100, 200 and 300 N for molar biting force. Finite element analysis was carried out in Solidworks, and readings of stresses and displacement were recorded. Wilcoxon rank sum test was applied and P-value of 0.05 was set for statistical analysis. Results: In this manuscript the authors have compared 3 internal fixation techniques in mandibular sagittal split osteotomy. There was a statistically significant difference for both stress and displacement readings between the 1.7 mm miniplate, the 2.0 mm bi-cortical screws and the 2.0 mm miniplate for all mandibular movements. For the 1.7 mm miniplate vs 2.0 mm bi-cortical screws, the stress reading was (P = 3.063e-08, W = 314), and for displacement was (P = 5.811e-05, W = 282). For the 1.7 mm miniplate vs 2.0 mm miniplate, the stress reading was (P = 9.862e-4, W = 263) and for displacement was (2.05e-2, W = 235). Conclusion: The 1.7 mm miniplate has adequate strength to be used in mandibular sagittal split osteotomy, although statistically less rigid when compared to the conventional 2.0 mm miniplate and 2.0 mm bi-cortical screws, especially in larger movements.
Ceramides and cytotoxic constituents from Ficus glumosa Del. (Moraceae)
Nana, Frédéric;Sandjo, Louis Pergaud;Keumedjio, Félix;Ambassa, Pantaléon;Malik, Rizwana;Kuete, Victor;Rincheval, Vincent;Choudhary, Muhammad Iqbal;Ngadjui, Bonaventure Tchaleu;
Journal of the Brazilian Chemical Society , 2012, DOI: 10.1590/S0103-50532012000300015
Abstract: chemical investigation of the stem bark of ficus glumosa (moraceae) yielded two new ceramides (2r,7e)-2-hydroxy-n-[(2s,3s,4r)-1,3,4-trihydroxyhexadecan-2-yl]hexacos-7-enamide and (2r)-n-{(2s,3s,4r,9z)-1-o-[(β-d-glucopyranosyl]-3,4-dihydroxyheptadec-9-en-2-yl}-2-hydroxypentacosanamide together with twenty one known compounds. the structures were established using nmr data, mass spectrometry, chemical transformation and by comparison with the reported data. twenty one compounds were further tested against the prostate cancer pc-3 cell line and six of them revealed cytotoxic effect. dongnoside e was the most active compound with an ic50 0.75 μmol l-1 against the cancer cells line pc-3 while the reference drug doxorubicin displayed 0.91 μmol l-1. this compound also proved to inhibit the cell growth of the fibrosarcoma cancer ht1080 (ic50 0.7 μmol l-1).
Kinetics of the Oxidation of Benzhydrols with Permanganate under Phase Transfer Catalysis in Organic Solvents  [PDF]
Koottil Muhammad Basheer, Joy Joseph, Thengumthanam D. R. Nair
Modern Research in Catalysis (MRC) , 2013, DOI: 10.4236/mrc.2013.22005
Abstract:

Kinetic studies of the oxidation of benzhydrol and some of its para-substituted derivatives using phase transferred permanganate in organic solvents that are immiscible with water have been carried out. The products of oxidation were the corresponding benzophenones. Kinetically first order dependence on the concentrations of substrate as well as the oxidant has been observed. The reaction rate was found to decrease with an increase in the dielectric constant of the organic solvent employed. The electronic effects of the substituents were found to be interesting. Both electron withdrawing and electron releasing groups at the para position of benzhydrol increased rate of the oxidation. The effects of different phase transfer catalysts (PTC) were also compared. The activation parameters have been evaluated and a mechanism consistent with the kinetic results has been proposed.

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