21 research outputs found
HexaaquaÂnickel(II) tetraÂaquaÂbisÂ(μ-pyridine-2,6-dicarboxylÂato)bisÂ(pyridine-2,6-dicarboxylÂato)trinickelate(II) octaÂhydrate
The title compound, [Ni(H2O)6][Ni3(C7H3NO4)4(H2O)4]·8H2O, was obtained by the reaction of nickel(II) nitrate hexaÂhydrate with pyridine-2,6-dicarbÂoxyÂlic acid (pydcH2) and 1,10-phenanothroline (phen) in an aqueous solution. The latter ligand is not involved in formation of the title complex. There are three different NiII atoms in the asymmetric unit, two of which are located on inversion centers, and thus the [Ni(H2O)6]2+ cation and the trinuclear {[Ni(pydc)2]2-μ-Ni(H2O)4}2− anion are centrosymmetric. All NiII atoms exhibit an octaÂhedral coordination geometry. Various interÂactions, including numerous O—H⋯O and C—H⋯O hydrogen bonds and C—O⋯π stacking of the pyridine and carboxylÂate groups [3.570 (1), 3.758 (1) and 3.609 (1) Å], are observed in the crystal structure
Evaluating the Potential of Alkalophilic Bacteria to Enhance Concrete Durability
Introduction: Nowadays, concrete has been widely used as one of the best and most practical building materials in various types of structures. Concrete permeability is a factor that reduces its stability and decreases the service life of concrete structures. This study has been conducted with the aim of finding bacteria able to repair concrete surface in order to reduce its permeability.
Materials and Methods: Isolated bacteria from alkaline soils of north and center of Iran were subjected to primary and secondary screening for producing urease enzyme and calcium carbonate precipitation. Selected isolates were cultured in specific broth medium for calcium carbonate precipitation. Then, the rate of their growth and calcium carbonate production were compared. Produced calcium carbonate, by the premier isolate, was verified using XRD. The ability of this isolate was evaluated in the repair of the concrete surface porosity and the reduction of its permeability by Scanning Electron Microscopy (SEM).
Results: The results of primary and secondary screening showed that Bacillus sp. UTMC 2623 produces the highest amount of calcium carbonate precipitation (8.8 g/L) in three days. Its XRD analysis confirmed the presence of crystalline calcium carbonate in dried bacterial precipitate. SEM analysis showed that this bacterium creates the best coating on the concrete surface along with the calcium source.
Discussion and conclusion: The present study is a report on the repairing activity of Bacillus sp. UTMC 2623 which can be used to find other native and promising microorganisms in concrete surface repair
Introduction of Fusarium sp. UTMC 5039 as a potent fungal strain for biosurfactant production and evaluation of its potential for crude oil bioremediation
Introduction: Biosurfactants are biological surface active agents which are used in many applications such as oil bioremediation of contaminated soils. Materials and methods: In this study, first soil samples were collected from crude oil contaminated regions of Iran. Fungal isolates were enriched in MSM medium supplemented with crude oil and purified and then all isolates were screened for biosurfactant activity. Then, the capacity of crude oil degradation in the selected isolate was measured using Total Petroleum Hydrocarbon (TPH) assay by spectrophotometry and FT-IR analysis. Finally, morphological and molecular identification was carried out by sequencing amplification of beta-tubuline beta-tubulin and ITS gene. Results: Among 40 purified fungal isolated, the isolate SH-02 was selected as the best strain according to the oil spreading and parafilm M test., This isolate was purified from petroleum contaminated soil of Arak refinery. Morphological and molecular identification revealed that this isolate has 99% similarity to Fusarium redolens in ITS geneand was deposited in the University of Tehran Microorganisms Collection under the accession number, UTMC 5039. Measurement of surface tension reduction by Du Nouy Ring method showed that Fusarium sp. UTMC 5039 can reduce surface tension to 26.6 mN/m and this reduction amount is significant compared with the previous reports. According to the obtained results from TPH and FTIR assays,  60 % of crude oil was degraded biodegradation was measured for by  Fusarium sp. UTMC 5039. Discussion and conclusion: The current study results indicate that Fusarium sp. UTMC 5039 has a high capacity in biosurfactant production and introduced as a potent fungal strain for crude oil bioremediation
Comparison of the Effects of Media-based and Face-to-face Cardiac Rehabilitation Training Programs on Self-efficacy in Patients Undergoing Coronary Artery Bypass Grafting
Background: Several complications may occur in patients after coronary artery bypass grafting (CABG) leading to decreased self-efficacy. Rehabilitation training is the best method for reducing the complications and increasing self-efficacy. Various educational techniques lead to different rehabilitation results and levels of self-efficacy. Improving these measures requires the selection of the most appropriate educational technique. Aim: This study aimed to compare the effect of two media-based and face-to-face cardiac rehabilitation training methods on self-efficacy in patients undergoing CABG. Method: This clinical trial was conducted among 60 patients, who were randomly assigned into two groups, in Imam Reza Hospital, Mashhad, Iran, 2017. Cardiac rehabilitation training program was implemented face-to-face or using a researcher-made multimedia upon admission, discharge, at the start of cardiac rehabilitation, and at the end of the 10th session for half-hour. A researcher-constructed questionnaire on self-efficacy was completed by the participants in the mentioned stages. Data analysis was performed in SPSS software, version 16. Results: The mean ages of the participants in the face-to-face and multimedia groups were 56.0±8.1 and 57.5±7.3 years old, respectively. No significant difference was observed in the self-efficacy scores of the patients upon admission (P=0.36). However, there was a significant difference between the groups at the post-intervention stage (
Seroprevalence of Immunoglobulin G antibodies against pertussis toxin among asymptomatic medical students in the west of Iran: a cross sectional study
<p>Abstract</p> <p>Background</p> <p>Pertussis is a highly communicable, vaccine-preventable respiratory infection. Immune response against this disease can be induced by infection or vaccination. Protection after childhood vaccination is minimal after ten years. Our aim was to assess pertussis immunity state in a population of healthy young medical students.</p> <p>Methods</p> <p>In this seroepidemiological survey, blood samples were obtained from 163 first-year medical students in Hamedan University, Iran. Serum level of IgG against pertussis toxin (IgG-PT) was measured by Enzyme-Linked Immunosorbent Assay (ELISA) method. For qualitative assessment, IgG-PT levels more than 24 unit (U)/ml were considered positive. Data was analysed qualitatively and quantitatively considering gender and age groups.</p> <p>Results</p> <p>There were 83 males and 80 females, with a mean age of 19.48 years, Prevalence of IgG-PT was 47.6% with mean level of 71.7 u/ml (95% confidence interval: 68.1–75.3). No statistically significant difference was observed with respect to sero-positivity of IgG-PT between males and females (45 cases (54%) vs. 34 cases (42%); P = 0.06). Mean IgG-PT levels in males and females were 84 U/ml and 58.8 U/ml, respectively (P = 0.91).</p> <p>Conclusion</p> <p>A considerable proportion of our study population with a positive history of childhood vaccination for pertussis was not serologically immune to pertussis. A booster dose of acellular pertussis vaccine may be indicated in Iranian, medical students regarding their serologic conditions and outstanding role in health care systems.</p
Large-stroke deformable MEMS mirror for focus control
We developed a novel large-stroke deformable mirror for focus control and spherical aberration correction. The mirrors fabricated using MEMS technology provide full range (150-200 µm in tissue) of focus scanning at high numerical aperture (N.A.=0.5-0.7) for confocal microscopy and optical coherence tomography (OCT). In addition to large stroke, low power consumption and high speed operation are other key factors of the developed devices. The impact of this project is broad since the miniaturized deformable mirrors have a wide range of applications. In addition to focus scanning in microscopes they can also be used in small form factor systems such as cell phone cameras and robot vision. Furthermore, laser based microscopes equipped with the focus control mirror may be useful for skin cancer diagnosis and treatment. This thesis consists of seven chapters. The first chapter introduces optical focus control and focus control elements. The second chapter describes different schemes for optical focus control in imaging systems including transmissive variable lenses. The principle of operation, fabrication, and characterization of electrostatic deformable mirrors are reviewed in Chapter 3. High-speed focus control mirrors with controlled air damping are discussed in Chapter 4. In this chapter a model adopted from the analysis of MEMS microphone is used to design the backplate of a MEMS deformable mirror. Moreover, electrostatic-pneumatic MEMS deformable mirrors are introduced in Chapter 5. Analytical model is developed for electrostatic-pneumatic actuation in order to design a MEMS mirror with two membranes. Applications of MEMS deformable mirrors are demonstrated in optical systems in Chapter 6. Finally, a summary and future work are discussed in Chapter 7. The fabrication process details are given in Appendix A
Solid Phase Extraction of Phenolic from Natural Water by Modified Polyacrylonitrile Fiber
Abstract: An analytical method for the determination of specific migration levels of phenolic antioxidants and one phosphite antioxidant in the aqueous food simulants established .This method involves solid-phase extraction (SPE) of the antioxidants with Modified polyacrylonitrile fiber (PANF) and their determination by liquid chromatography (LC) with diode-array detection.Modified polyacrylonitrile fiber (PANF) was prepared by adding of acrylic fibers to ethanolamine (MEA) with different concentration solutions.The stability of a chemically modified PANF especially in concentrated hydrochloric acid which was then used as a recycling and pre-concentration reagent for further uses of Modified polyacrylonitrile fiber. phenolic antioxidants was found to exhibit the highest affinity towards extraction by these Modified polyacrylonitrile fiber phases. The potential applications of Modified polyacrylonitrile fiber for selective extraction of phenolic antioxidants to occur from aqueous solution were successfully accomplished as well as pre-concentration of low concentration of phenolic antioxidants (40 pg ml -1 ) from natural tap water with a pre-concentration factor of 200 for phenolic antioxidants off-line analysis by determination by liquid chromatography (LC) analysis
Effect of Mobile Phone Microwaves on Fetal Period of Balb-C Mice in Histological Characteristics of Hippocampus and Learning Behaviors
Objective(s)The possible risks of radio-frequency electromagnetic fields (EMF) for the living organisms and human body are a growing concern for our society. In this study, we examined the possibility of changes in working memory and hippocampal histological characteristics effects in mice brain following whole body exposure to microwave radiation.Materials and MethodsDuring gestation period, we exposed mice for 4 hr to Global system for mobile communications (GSM), Specific Absorption Rate (SAR) of 200 mW/kg. Pregnant control mice were sham-exposed or free in a cage without further restraining. Three month after exposure animals were prepared for behavioral (Radial Arm Maze (RAM) and Morris Water Maze (MWM)) and histological studies.ResultsThe results showed that microwave exposed mice were slower than sham, and control in finding the platform. Analyses of error rates in RAM and MWM performance revealed significant differences which emphasize the effect of acute exposure to pulsed microwaves in deficit of spatial reference memory in the mice. However in this study exposed group didn’t show any statistically significant loss of hippocampal CA1, CA3 neurons versus controls or sham. ConclusionWe conclude that there is evidence from the current study that exposure to MW radiation under parameters examined caused decrements in the ability of mice to learn the spatial memory task