Thirty one samples of gum swabs were collected from patients with tooth caries (5-30 years old) from the College of Science (Biology department )- University of Baghdad- Iraq for the period from October 2018 to December 2018. , The samples were transported, after inoculation in a transport media (nutrient broth), to the laboratory of the College of Science and then cultured on mannitol salt agar and blood agar). The isolates belonging to Staphylococcus spp. were identified by biochemical tests and Vitek 2 compact system, while the more antibiotic resistant isolates were identified by using Polymerase Chain Reaction(ï´¾PCR) and sequencing of 16SrRNA . The results showed sharp UV absorption peaks at 330 - 340nm and AFM at 56 nm. Transmission Electron Microscope (TEM) results showed that lemon silver nanoparticles (NPs) are spherical in shape. The results also demonstrated that the silver NPs have a higher antibacterial activity with a diameter of inhibition zone that reached 16mm as compared with the common three mouthwash and toothpaste brands (Colgate, Crest and Close up) that had inhibition zone values of 5-8mm.
Silver nanoparticles (Ag-NPs) have been prepared using the electro-chemical
method. The experimental setup of this technique consist of two electrodes of pure
silver (99.2 %), the applied voltage on the electrodes is 20 V and the current through
the colloidal was about 0.4 Amp. The silver nanoparticles crystallization has been
studied; the crystalline structure appears Face center Cubic. The optical properties of
silver nanoparticles are strongly affected by the Local Surface Plasmon Resonance
(LSPR). The wavelength of maximum absorption band for an Ag NPs have a range
(~350nm-550nm).
This study proposed to synthesize iron oxide by biological method nanoparticles. The E.coli is used to reduce Ferric chloride salt into iron particles. The formation of iron oxide nanoparticle was initially monitored by visual observation and then characterized with the help of various characterization techniques such as Uv-vis spectroscopy, (AFM) and (FTIR) analysis, which revealed that the biosynthesized iron oxide nanoparticles were spherical within size 27.7 nm. Optimization of iron oxide nanoparticle biosynthesis by E.coli was performed for parameters (temperature and pH) and the results revealed that temperature 37°C and pH 5 were the optimum conditions for iron oxide nanoparticales biosynthesis by E.coli.<
... Show MoreThis study was conducted to investigate the antibacterial activity of green synthesized copper oxide nanoparticles (CuO NPs) using Aloe vera. Initially, bacteria were collected from clinical samples of patients having otitis media infection and the isolates were identified at the species level following biochemical tests. Copper oxide nanoparticles were prepared by green synthesis using Aloe vera leaves and characterized using UV- visible spectroscopy at 260 nm peak. The shape and size were determined by using transmission electron microscopy (TEM) and the dimensions of the particles were more precisely determined by using scanning electron microscopy (SEM) and x-ray diffraction (XRD). Different concentrations of nanopa
... Show MoreNanofluids (dispersion of nanoparticles in a base fluid) have been suggested as promising agents in subsurface industries including enhanced oil recovery. Nanoparticles can easily pass through small pore throats in reservoirs formations; however, physicochemical interactions between nanoparticles and between nanoparticles and rocks can cause a significant retention of nanoparticles. This study investigated the transport, attach, and retention of silica nanoparticles in core plugs. The hydrophilic silica nanoparticles were injected into limestone core as nanofluid of different nanoparticles size (5 nm, and 20 nm), concentration (0.005 – 0.1 wt% SiO2), and base fluid salinity (0 – 3 wt% NaCl) at different temperatures (23, and 50 °C). D
... Show MoreBackground. Nanocoating of biomedical materials may be considered the most essential developing field recently, primarily directed at improving their tribological behaviors that enhance their performance and durability. In orthodontics, as in many medical fields, friction reduction (by nanocoatings) among different orthodontic components is considered a substantial milestone in the development of biomedical technology that reduces orthodontic treatment time. The objective of the current research was to explore the tribological behavior, namely, friction of nanocoated thin layer by tantalum (Ta), niobium (Nb), and vanadium (V) manufactured using plasma sputtering at 1, 2, and 3 hours on substrates made of 316L stainless steel (SS),
... Show MoreIn this work gold nanoparticles (AuNPs), were prepared. Chemical method (Seed-Growth) was used to prepare it, then doping AuNPs with porous silicon (PS), used silicon wafer p-type to produce (PS) the processes doping achieved by electrochemical etching, the solution etching consist of HF, ethanol and AuNPs suspension, the result UV-visible absorption for AuNPs suspension showed the single peak located at ~(530 – 521) nm that related to SPR, the single peak is confirmed that the NPs present in the suspension is spherical shape and non-aggregated. X-ray diffraction analysis indicated growth AuNPs with PS. compare the PS layer without AuNPs and with AuNPs doped for electrical properties and sensitivity properties we found AuNPs:PS is more
... Show MoreThe nanostructured MnO2 /carbon fiber (CF) composite electrode was prepared using the anodic electrodeposition process. The crystal structure and morphology of MnO2 particles were determined with X-ray diffraction and field-emission scanning electron microscopy. The electrosorptive properties of the prepared electrode were investigated in the removal of cadmium ions from aqueous solution, and the effect of pH, cell voltage, and ionic strength was optimized and modeled using the response surface methodology combined with Box–Behnken design. The results confirm that the optimum conditions to remove Cd(II) ions were: pH of 6.03, a voltage of 2.77 V, and NaCl concentration of 3 g/L. The experimental results showed a good fit for the Freundli
... Show MoreThis paper reports an experimental study regarding the influence of vertical oscillations on the natural convection heat transfer from a vertical channel. An experimental set-up was constructed and calibrated; the vertical channel was tested in atmosphere at 25o
C. The channel-to-ambient temperature difference was varied with the power supply to the electrical heater ranging between
15W to 70W divided into five levels. Data sets were measured under different operating condition from a test rig under six vibrating velocities (VVs) levels ranging from (5-30 m/s) in addition to the stationary state. The results show that the maximum heat transfer enhancement factor (E) occurs at Rayleigh number (Ra=2.328×103 ) and vibrational Reynol
Background : It had been indentified by histological, histochemical and morphometrical studies that peganum harmala is a mammogenic herb and borage officinalis is a lactogenic one . To complete our investigation about these two herbs , we performed electron microscopical study . Materials and methods : Rats were grouped according to their physiological status into three groups . Each group was subdivided in to three subgroups : one control and two experimental . The two experimental group were treated daily; the 1st one with an aqueous extract of peganum harmala seeds and the 2nd with an aqueous extract of borage officinalis flowers . After two weeks of treatment , mammary glands were employed for electron microscopical study . Resu
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