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In this work, the electrokinetic properties of asphaltene particles have been investigated. Micro-electrophoresis method by applying DC electric field, was utilized to different mixtures containing asphaltene to determine its electric charge. It was observed that in the case of using n-heptane and its mixture with toluene (heptol), the asphaltene particles were showed to be positively charged however for toluene itself, they expressed no tendency toward the electrodes. While it is expected that larger asphaltene aggregates carry higher electric charge, the results contradictorily showed that they are mainly governed by gravity rather than electro-static force and that “aggregation” reduces the charge density of asphaltene particles. Using a digital microscope equipped with image processing software, the average net electric charge of each asphaltene molecule was calculated to be 5 . 62 × 10 - 28 C m o l e c u l e or 3 . 51 × 10 - 9 ē m o l e c u l e . As this value is much less than 1ē, it can be concluded that asphaltene molecules do not possess intrinsic electric charge and the apparent charge is mostly induced through the medium, generated by rearrangement of asphaltene molecular structure. Thereafter, based on calculated charge and considering governing forces (gravity, friction and electric force), the electrophoretic mobility of asphaltene particles in dynamic mode was mathematically modeled and verified under different electric field intensities. The results illustrated satisfactory agreement with the obtained experimental data. Knowing the asphaltene electric charge, the magnitude of streaming potential can be calculated, subsequently the model will be able to predict the velocity ranges at which colloidal asphaltene flocculation is possibly avoided. Finally the effect of flow rate, electric potential and solvent composition was investigated on electrophoretic mobility. It was found that, the higher the fluid flow rate, the greater is the mobility. However, increasing the electric potential resulted in electrophoretic mobility reduction of asphaltene particles. Moreover, critical increase of electrophoretic mobility was observed for n-heptane contents of more than 50 wt.% in heptol, which refers to the onset point of asphaltene nano-aggregates.

MWCNTs-C-PO3H2 has been used as an efficient, heterogeneous and reusable nanocatalyst for synthesis of acylals from aldehydes under solvent-free conditions at room temperature. A wide range of aldehydes was studied and corresponding products were obtained in good to excellent yields in short reaction times. Nanocatalyst can be easily recovered by centrifuge and reused for subsequent reactions for at least five times without deterioration in catalytic activity. The major advantages of the present method are high yields, short reaction time, recyclable catalyst and solvent-free reaction conditions at room temperature.

An efficient and general method has been developed for synthesis of 1- and 5-substituted 1H-tetrazoles from nitriles and amines using magnetite nanoparticles immobilized Salen Cu(II) as an efficient and recyclable catalyst. The structural and magnetic properties of functionalized magnetic silica are identified by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM) instruments. NMR, FT-IR, elemental analysis and XRD were also used for identification of these structures. Nanocatalyst can be easily recovered by a magnetic field and reused for subsequent reactions for at least 7 times with less deterioration in catalytic activity.

Curcumin has protective effects on a variety of CNS injury models. Our purpose was to assess the effects of curcumin on the dorsal root ganglion (DRG) and functional recovery in sciatic nerve crush (SNC) of rats.The fifth lumbar DRG was removed 28 days after SNC. Sciatic functional index (SFI) and also the DRG structure were evaluated, using stereological methods to assess the effects of curcumin.The volume and number of A- and B-cells were reduced in the SNC as compared with the sham-operated animals. In curcumin treated rats, the volume decreased but in a lesser extent and it was ∼10% and ∼15% higher on the average in comparison with the non-treated SNC (P0.04). In curcumin treated rats, the number of cells also decreased but in a lesser extent and it was ∼17% and ∼36% higher in comparison with the non-treated crushed animals (P0.02). The surface area of A- and B-cells reduced in the SNC and SNC plus curcumin in comparison with the sham-operated rats (P0.01). The number of satellite cells was reduced in the SNC as compared with the sham-operated animals. In curcumin treated rats, the number of satellite cells decreased but in a lesser extent and the number of satellite cells was ∼19% higher in comparison with the non-treated (P0.02). SFI test shows that the motor function of the rats treated with curcumin significantly improved at 21st days after sciatic nerve crush.The results demonstrate that curcumin promotes the functional recovery and has a neuroprotective effect on the DRG after sciatic nerve injury in the rats.

Background: Formaldehyde (and its compositions) is a chemical substance that is widely used in chemical industries (detergents, cosmetics and so on), medicine (for sterilization of operation room and its instruments and fixation of histological specimens and cadavers) and even in textiles and papers. Methods: In recent years many studies have been done in formalin effects on people health. But anybody did not study formalin effects on nose and throat in persons that have direct contact with this substance in Iran. For this reason; questionnaires were sent to personnel of anatomical sciences departments in medical schools were selected as experimental group and personnel of high schools as control group. Questionnaires were prepared that had following indexes: Nasal signs (runny nose and smell sense changes), throat signs (sore throat), occupation, sex, age, formalin contact (duration and direct or indirect contact) and diseases history. Data were analyzed by Chi-square test. Results: Results showed that contact with formalin causes decrease (or loss) of smell sense and increase of runny nose and sore throat. These changes have direct relation with contact duration and direct contact. Relation between contact with formalin and these changes is significant (P