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101.
S. S. Ibrahim A. M. El Kammar A. M. Guda T. R. Boulos A. Saleh 《Particulate Science and Technology》2019,37(2):141-150
A thorough characterization of a glauconite sample collected from a core drilled on the southeast edge of the Abu Tartur Plateau in the Western Desert of Egypt was carried out. The sample, which represents the upper part of the Campanian Duwi Formation, was examined using a petrographic polarizing microscope as well as X-ray diffraction and X-ray fluorescence methods. The magnetic behavior of the different size fractions was tested using a Frantz isodynamic separator prior to the beneficiation process. This process was conducted by both magnetic separation, using an Eriez rare earth roll magnetic separator, and heavy liquid gravity methods during the search for a higher grade of K2O. A correlation between the mineral composition and magnetic behavior of the particles was shown. Two potassium oxide concentrates were obtained, having 6.8 and 6.22% K2O, from an original sample containing 4.41% K2O by weight. A blend of both products yielded a product having 6.42% K2O with an overall recovery of 41.5%, which may satisfy the requirement of a natural fertilizer. The association of this product with phosphate and pyrite will help to remediate alkaline soils. In addition, a sulfur-rich coproduct containing 11.32% S with a recovery of 31.6% was obtained. 相似文献
102.
Mohammed M. Mehanna Mohamad Ibrahim Shabarek Hoda A. Elmartadny 《Drug development and industrial pharmacy》2019,45(3):485-497
Pravastatin is a promising drug utilized in the treatment of hyperlipidemia, yet, its main clinical limitation is due to gastric liability which fractions its oral bioavailability to less than 18%. The purpose of the current study is to encapsulate pravastatin into Eudragit®-based spray-dried microparticles aspiring to overcome its acid liability. With the aim to optimize the microparticles, formulation and process parameters were studied through acid resistance challenging test. Physicochemical characterization of the optimized spray-dried pH-sensitive microparticles namely; in-vitro dissolution, surface morphology, compatibility, and solid-state studies were performed. Moreover, in-vivo evaluation of the microparticles and accelerated stability studies were carried out. The results outlined that polymer to drug ratio at 5:1 and pravastatin concentration at 1%w/w in spray-drying feed solution showed 38.55% and 53.97% encapsulation efficiency, respectively. The significance of process parameters specifically; the flow rate and the inlet temperature on microparticles surface integrity were observed, and optimized until encapsulating efficiency reached 72.37%. The scanning electron microscopical examination of the optimized microparticles illustrate uniform smooth surface spheres entrapping the drug in an amorphous state as proved through Differential Scanning Calorimetry (DSC) and Fourier Transfer Infrared (FTIR) studies. The in-vivo evaluation demonstrated a 5-fold enhancement in pravastatin bioavailability compared to the marketed product. The results provided evidence for the significance of spray-dried pH-sensitive microparticles as a promising carrier for pravastatin, decreasing its acid liability, and improving its bioavailability. 相似文献
103.
104.
Guven Ibrahim Cinar Kenan 《International Journal of Mechanics and Materials in Design》2019,15(4):695-714
International Journal of Mechanics and Materials in Design - A method based on X-ray micro-CT was introduced to create realistic representative volume elements (RVE) for particulate-filled... 相似文献
105.
Chin Ren Jie Lai Sai Hin Ibrahim Shaliza Wan Jaafar Wan Zurina Elshafie Ahmed Hussein Kamel Ahmed 《Engineering with Computers》2019,35(4):1409-1418
Engineering with Computers - The presence of wall slip in concentrated suspensions affect the rheological measurements such as shear stress, shear rate, and viscosity. The measured shear rate will... 相似文献
106.
Ibrahim I. T. Attallah K. H. Elsaid M. Fahmy M. H. Abo Zaid L. A. 《Radiochemistry》2019,61(2):220-225
Radiochemistry - Aspirin, one of nonsteroidal anti-inflammatory analgesic drugs, was labeled with 125I with a labeling yield of 85.5% under the following conditions: pH 9, 100 mg of the substrate,... 相似文献
107.
Correlation of In Vivo and In Vitro Assay Results for Assessment of Free Radical Scavenging Activity of Green Tea Nutraceuticals 下载免费PDF全文
Heba‐Alla H. Abd‐ElSalam Medhat A. Al‐Ghobashy Muhammad Al‐Shorbagy Noha Nassar Hala E. Zaazaa Mohamed A. Ibrahim 《Journal of food science》2016,81(7):C1707-C1715
Green tea (GT)‐derived catechins; epigallocatechin gallate (EGCG) in particular are commonly used nutraceuticals for their free‐radical scavenging activity (FRSA). The influence of photodegradation on the protective power of GT nutracenticals against oxidative stress was thoroughly explored. Photodegradation of GT extracts was carried out and monitored using orthogonal stability‐indicating testing protocol; in vitro and in vivo assays. Total polyphenol content (TPC) and FRSA were determined spectrophotometrically while EGCG was selectively monitored using SPE‐HPLC. In vivo assessment of photodegraded samples was investigated via measuring a number of biomarkers for hepatic oxidative stress and apoptosis (caspase‐3, inducible nitric oxide synthase, nitric oxide, mitogen‐activated protein kinase, glutathione, thiobarbituric acid reactive substances, nuclear factor kappa beta, and nuclear factor erythroid 2‐related factor) as well as liver damage (alanine transaminase and aspartate transaminase) in serum of rats previously subjected to oxidative stress. Results showed complete degradation of EGCG in photodegraded green tea samples with no correlation with either TPC or FRSA. On the other hand, in vivo assay results revealed not only loss of activity but formation of harmful pro‐oxidants. Photostability was found crucial for the protective effect of GT extract against lead acetate insult. Results confirmed that careful design of quality control protocols requires correlation of chemical assays to bioassays to verify efficacy, stability, and most importantly safety of nutraceuticals. 相似文献
108.
Melt Production and Antimicrobial Efficiency of Low-Density Polyethylene (LDPE)-Silver Nanocomposite Film 总被引:1,自引:0,他引:1
Maryam Jokar Russly Abdul Rahman Nor Azowa Ibrahim Luqman Chuah Abdullah Chin Ping Tan 《Food and Bioprocess Technology》2012,5(2):719-728
Colloidal silver nanoparticles with a size of 5.5 ± 1.1 nm were prepared by chemical reduction using polyethylene glycol (PEG).
Silver nanoparticles were incorporated into low-density polyethylene (LDPE) by melt blending and subsequent hot pressing at
140 °C to produce nanocomposite film with an average thickness of 0.7 mm. PEG was added at 5% weight of polymer as a compatibilizer
agent in order to prevent agglomeration and provide uniform distribution of nanoparticles in polymer matrix. Antimicrobial
activity of silver nanocomposites against Escherichia coli ATCC 13706, Staphylococcus aureus ATCC12600, and Candida albicans ATCC10231 was evaluated by semi-qualitative agar diffusion test and quantitative dynamic shake flask test. Mechanical properties
of nanocomposites were not significantly different from silver-free LDPE-containing PEG films (p > 0.05), and silver nanoparticles did not form chemical bonding with the polymer. LDPE-silver nanocomposite samples by more
than 6.69 ppm silver nanoparticles showed considerable antimicrobial clear zone. LDPE-silver nanocomposite affected growth
kinetic parameters of the examined bacteria and is more efficient on S. aureus than E. coli. Polyethylene-silver nanocomposites containing 22.64 ppm silver nanoparticles could reduce 57.8% growth rate and 23.3% maximum
bacterial concentration and increase 35.8% lag time of S. aureus. This study shows the potential use of LDPE-silver nanocomposite as antimicrobial active film. Antimicrobial efficiency of
silver nanocomposite depends on silver nanoparticles concentration; however, high level of silver nanoparticles may lead to
weakening of mechanical properties. 相似文献
109.
Sr2La3Nb1?x Ta x Ti4O17 (0 ≤ x ≤ 1) ceramics were processed via a solid-state mixed oxide route. Sr2La3Nb1?x Ta x Ti4O17 (0 ≤ x ≤ 1) solid solutions were single phase in the whole range of x values within the x-ray diffraction (XRD) detection limit. The microstructure comprised elongated and needle-shaped grains. The ceramics exhibit relative permittivity (ε r) of 73 to 68.6, product of unloaded quality factor and resonant frequency (Q u f 0) of 7100 GHz to 9500 GHz, and temperature coefficient of resonant frequency (τ f) of 78.6 ppm/°C to 56.6 ppm/°C. 相似文献
110.
Muzaffer Erdoğan Ibrahim Gunes Alper Dalar 《Transactions of the Indian Institute of Metals》2014,67(2):291-297
In this study, corrosion behaviors of GS18NiMoCr36 (GS 18) and GS32NiCrMo6.4 (GS 32) gear steels borided in Ekabor-II powder at the temperature of 950 °C for 2 and 6 h were investigated in a 6 % M HCI acid solution. The boride layer was characterized by optical microscopy, X-ray diffraction technique and the Micro-Vickers hardness tester. X-ray diffraction analysis of boride layers on the surface of the steels revealed the existence of FeB, Fe2B, CrB and Cr2B compounds. The thickness of the boride layer increases by increasing boriding time for gear steels. The hardness of the boride compounds formed on the surface of the steels GS 18 and GS 32 ranged from 1,728 to 1,905 HV0,05 and 1,815 to 2,034 HV0,05 respectively, whereas Vickers hardness values of the untreated steels GS 18 and GS 32 were 335 HV0,05 and 411 HV0,05, respectively. The corrosion resistance of borided gear steels is higher compared with that of unborided steels. The boride layer increased the corrosion resistances of gear steels 4–6-fold. 相似文献