فهرست مطالب

Bio-Inorganic Hybrid Nanomaterials - Volume:2 Issue: 4, winter 2014

International Journal Of Bio-Inorganic Hybrid Nanomaterials
Volume:2 Issue: 4, winter 2014

  • تاریخ انتشار: 1393/03/28
  • تعداد عناوین: 8
  • Alireza Badiei*, Golriz Dadashi, Hossein Attar, Nastaran Hayati, Roodbari Pages 471-476
    In this work, the effect of immobilization of bread yeast (Saccharomyces cerevisiae) by sol-gel technique combined with functionalized nanoporous silica was investigated in different weight ratios of silica containing materials (TMOS: LUS-1). The activities of immobilized yeast in days after immobilization were examined. The results showed immobilization maintain the yeast life for a longer time. The functionalization by C18 functional group improved the environmental conditions for yeast life. These results indicate that the immobilization technique in the gel matrix and porous solid is a good system to develop industrial fermentations.
    Keywords: Nanoporous silica, Sol, gel, Bread yeast, LUS, 1, Fermentation, Immobilization, Mesopore
  • Nasser Shahtahmasebebi, Ahmad Kompany Pages 477-483
    Metal nanoshells consists of a dielectric core surrounded by a thin noble metal shell, possess unique optical properties that render nanoshells attractive for use in different technologies. This paper reports a facile method for growth of small gold nanoparticles on the functionalized surface of larger silica nanoparticles. Mono-dispersed silica particles and gold nanoparticles were prepared by the chemical reduction method. The size of the shell nanoseeds could be altered by repeating the stage of reducing HAuCl4 on Au/APTES/silica particles, and the time for which they react. The nanocore-shell particles prepared were studied using scanning electron microscopy (TEM), UV–Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR) and PL spectrophotometer. The TEM images indicated that by growing gold nanoseeds over the silica cores a red shift in the maximum absorbance of UV-Visible spectroscopy is observed. Furthermore, a remarkable intensification happens in the PL spectra of silica@Au NPs in comparison with that of bare silica NPs.But,the existence of gold nanoseeds on the silica particles surfaces does not change the PL spectra peaks of these nanoparticles.
    Keywords: Core, shell, Silica, Gold, Nanoparticle, Surface functionalized, Initial growth
  • Mahnaz Hashemiravan*, Maryam Saberi, Nazanin Farhadyar Pages 485-490
    Various compounds have been used for microencapsulating of fish oilso far, but in thiswork for the first time, inulin and casein which are both known for their functional properties, were used as the coating materialof fish oil.This study aimed to investigate the properties of nano-emulsions (droplet size measurements and pH) based on changes in the concentration and type of wall and their effects on the morphology and structure of microcapsuleswere investigated.Microencapsulation of fish oil was done in 3 steps. First,the wall with 5 different concentrations of inulin and casein were mixed with distilled water.In the next step, an ultrasound generator was usedwith an intensity of 24kHz for 120 seconds to prepare nano-emulsions and finally the emulsions were converted into powder in a lab-scale spray dryer.The emulsion pH was measured and emulsion droplet size was examined by a particle size analyzer. The microstructures of the powders were analyzed by scanning electron microscopy (SEM). The results showed that the type and concentration of the compounds used as the wallare effective on the properties of nano-emulsion.Comparing the two compounds and their concentrations demonstrated that caseinhas more desirable properties, as if the lowest size of 95/733nm corresponds to the treatment with 20% casein (p<0.05). Moreover, a significant negative correlation was observed between the size and pH of the nano-size emulsion of fish oil. The comparison between 4% (w/w) and 8% (w/w) fish oil, showed that byincreasingthe ratio of core to wall from 5:1 to 5:2, the size of nano-emulsion significantly reduced (p<0.01).Microencapsulatedparticles containing higher concentrations of casein showed much less wrinkle and depression compared to the samples containing higher concentrations of inulin, because of the smaller size of the nano-emulsions containing higher concentrations of casein. In this study the emulsion droplet size wasat the nano-scale and the images showed the significance of wall material properties and their concentrationsaffecting droplet size and morphology of microcapsules.
    Keywords: Casein, Inulin, Fish oil, Nano, emulsion, Scanning electron microscope
  • Shaghayagh Marzban*, Saeid Abedini Khorrami Pages 491-494
    Synthesis of BaFe12O19 magnetic nano particles via precipitation in different pH conditions have been reported. The certain molar ratio of Fe/Ba = 12 selected and sodium hydroxide was used as a precipitant agent. X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and vibrating sample magnetometer (VSM) were used to consider the structural, morphological and magnetic properties of barium hexaferrite nano-particles, respectively. Results demonstrated that pH plays an important role in phase composition; so affected sample properties. The broad hysteresis loop shows that the barium hexaferrite powder was in good crystalline nature.
    Keywords: Barium Hexaferrite, Co, precipitaion, pH, Magnetic Properties, Nanoparticles, Hard Ferrites, XRD
  • Ali Moghimi Pages 495-502
    A organic-solution-processable functionalized-graphene (SPFGraphene) material has been studied on pre-concentration and determination of trace Mo(II)ions. In this process, the effects of pH solution, elution conditions on pre-concentration of trace Mo(II) were studied and the effect of interfering ions was also investigated. A selective method for the fast determination of trace amounts of Mo (II) ions in water samples has been developed. method has been developed for preconcentration of Mo on organic-solution-processable functionalized-graphene (SPFGraphene) adsorbent in the pH range 5.0–10.0, prior to its spectrophotometric determination, based on the oxidation of bromopyrogallol red at λ = 517 nm. This method makes it possible to quantitize Mo in the range of 6.9×10−9 to 2.7×10−5 M, with a detection limit (S/N = 3) of 1.78×10−9 M. This procedure has been successfully applied to determine the ultra-trace levels of Mo in the environmental samples, free from the interference of some diverse ions. The precision, expressed as relative standard deviation of three measurements is better than 3.0%.
    Keywords: Preconcentration, Micro crystalline, Nano graphene, Mo(II), SPE, FAAS, Organic, solution, Functionalized
  • Mohammad Javad Taghizadeh*, Khosrow Jadidi Pages 503-510
    The catalytic highly regio-, diastereo-, and enantioselective synthesis of a small library of spiropyrrolizidineoxindolesvia a four-component 1,3-dipolar cycloaddition reactionof azomethineylides, derived from isatin, with electron-deficient dipolarophilewas described. The process occurs at room temperature in aqueous ethanol as a green solvent and in the presence of a bidendatebis(imine)–Cu(II)triflate complex as catalyst.The reaction mechanism is discussedon the basis of the assignment of the absolute configuration of the cycloadducts.
    Keywords: Chiral spiro, oxindolopyrrolizidines, Asymmetric 1, 3, dipolar, Chiral auxiliaries, Azomethineylide, Three, component reaction, Proline, Sarcosine
  • Farah Nameni Pages 511-515
    Skeletal muscle may develop adaptive chaperone and enhancementdefense system through daily exercisestimulation. The present study investigated resistance and exhaustion training alters the expression of chaperoneproteins. These proteins function to maintain homeostasis, facilitate repair from injury and provide protection. Exercise-induced production of HSPs in skeletal muscle and peripheral leukocytes and, it may provide insight into the mechanisms by which exercise can provide increased protection against stressors. The aim of this study was to examine the effect of 2 types exercise trainingon HSP70 expression.Nineteen training female in 2 groups taking part in the intervention volunteered to give blood samples. Levels of chaperone proteins weremeasured in response to resistance and exhaustion training.HSP70 levels were increased, immediately and 2 h after Progressive training but decreased after resistance training. The data showed that human skeletal muscle responds to the stress of a single period of Progressive trainingby up regulating and resistance training by down regulating expression of HSP70.Physical exercise can elevate core temperature and muscle temperatures and the expression pattern of HSP70 due to training status may be attributed to adaptive mechanisms.
    Keywords: Heat shock proteins, Exercise training, Immune system
  • Meysam Sadeghi*, Mirhassan Hosseini Pages 517-524
    This work undertakes the study of the detoxification reactions of O, S-dimethyl phosphoramidithioate (methamidophos) as an organophophorus insecticide on the 14.7 wt% magnetite (Fe3O4) nanoparticles/Ag-NaY faujasite molecular sieve zeolite (FMSZ) composite. The influence of solvent (methanol, acetonitrile and n-hexane) on the detoxification potential of composite was investigated. For this survey, in the first step, sodium type-Y (NaY) zeolite was synthesized by hydrothermal method (HM). Then, Ag-NaY zeolite was prepared from NaY zeolite by ion-exchange method (IEM). In the next step, Fe3O4 nanoparticles (NPs) were incorporation and deposited on the Ag-NaY zeolite structure by using precipitation method (PM). The synthesized samples were characterized by SEM, EDAX and XRD techniques. The GC-FID and IR analyses results demonstrated that about 99% of methamidophos was detoxified (adsorbed) via this composite at n-hexane solvent after 10 h. On the other hand, the results for the acetonitrile and methanol solvents were lower. It seems that a nonpolar solvent transfer to the reactive surface site on the composite without occupying and blocking of these sites.
    Keywords: Detoxification, O, S, dimethyl phosphoramidithioate (methamidophos), Insecticide, magnetite (Fe3O4) nanoparticles, Ag, NaY faujasite molecular sieve zeolite (FMSZ), Composite