Electrosynthesis and In Situ Spectroelectrochemistry of Conducting o-aminophenol-p-aminophenol Copolymers in Aqueous Solution

Copolymerization of o-aminophenol (o-AP) and p-aminophenol (p-AP) in aqueous sulfuric acid solution was electrochemically performed using cyclic voltammetry on gold electrode. Copolymerization was carried out at different feed concentrations of homo monomers. The obtained films were characterized with cyclic voltammetry, in situ resistivity measurements, in situ UVVis-spectroscopy, FT-IR spectroscopy, and scanning electron microscopy (SEM) Aminophenols are interesting members of the class of substituted aniline. The hydroxyl group in the phenyl ring can be oxidized to quinine and quinine can be reduced again. Thus, unlike aniline and other substituted aniline, they have two groups (NH 2 and OH), which could be oxidized. Therefore, they could show electrochemical behavior resembling anilines 1-3 and/or phenols. . 6 Several researchers have studied the electropolymerization of ortho, meta and para aminophenol on different electrode materials (platinum, gold, carbon, etc.) and solvents. 7-18 Poly (o-aminophenol) (P(o-AP)) has attracted most attention due to the formation of electro active polymer during its chemical and electrochemical oxidation. P(o-AP) has been investigated with electrochemical, spectroelectrochemical, and impedance measurements Experimental Reagents and solvents.-The chemical used were of reagent grade. o-AP and p-AP (99%) were obtained from Merck and used without further purification. Sulfuric acid (Merck) was used as received. Doubly distilled water was used to prepare solutions. Electrochemistry, UV-visible, and FTIR spectroscopy.-Cyclic voltammetry (CV) was performed using a Behpajoh model BHP/2062 and an Atolab model PGSTAT 20 potentiostat/galvanostat. A threecompartment electrochemical H cell with glass frit separators between the cell compartments was used for voltammetry studies. Working and auxiliary electrodes were gold sheets of ∼0.4 and 1.0 cm 2 surface area (from AZAR electrode), respectively. For UV-vis spectroscopy optically transparent ITO-coated glass sheets (surface area is 0.7 × 4.5 cm 2 , Praezisions Glas & Optik, Germany, R = 20 ± 5 cm −2 ) were used as working electrodes in a standard 10-mm cuvette. A gold wire served as counter electrode, the reference electrode was connected via a plastic tube. The saturated calomel electrode (SCE) was used as reference electrode in all experiments. UV-vis spectra were recorded with the polymer and copolymer films deposited from the electrolyte solutions. A UV-vis spectrophotometer Perkin Elmer 55 OSD with a cuvette with the same solution and an uncoated ITO glass in the reference beam was used. Spectra were recorded at increasingly positive electrode potentials; in a few cases, spectra were recorded in the negative-going potential direction also in order to test reversibility. The stability of the optical response was checked frequently in th

Nickel nanoparticles coated on the exfoliated graphene layer as an efficient and stable catalyst for oxygen reduction and hydrogen evolution in alkaline media

In this work, we report simultaneous electrochemical exfoliation of graphite powder using SDS, anionic surfactant salts, and cyclic potential to prepare graphene on carbon paper. Then, Nickel is electro-reduced into graphene nanosheets on carbon paper and also on the bare carbon paper to use in alkaline media for hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR). Afterward, graphene and Ni-graphene are characterized using scanning electron microscopy, atomic force microscopy (AFM) and electrochemical technique. SEM images show the Cauliflower structure of Ni in the absence of graphene and nanoparticle shapeless in the presence of smooth graphene. The electrochemical results show an excellent catalytic activity of Ni-graphene/ carbon paper with an over potential of 90 mV (Versus Ag/AgCl), which is lower than the literature value for Ni in alkaline electrolyte for HER (120 mV dec ^−1 ). The effect of graphene support on the electrochemical impedance spectroscopy response, activation energy and HER activity of the samples are investigated carefully. Finally, we prepare a novel gas diffusion electrode by using Ni pasted on carbon paper for the ORR in fuel cells and compared it with standard Pt/C catalysts using linear sweep voltammetry

Evaluation of Ergonomic Factors on the Prevalence of Musculoskeletal Disorders Between the Urban and Out of Urban Drivers in Ilam Province

Introduction: Ergonomic factors can increase the prevalence of musculoskeletal disorders. The aim of this study was to determine the effects of the ergonomic variables on the prevalence of musculoskeletal disorders between the urban and out of urban drivers in Ilam province. Materials and Methods: The population studied in this research including 251 peoples of the urban and out of urban drivers in Ilam province in 2007-2008. The different variables such as driving state, seat position, driver cab condition, the diameter of the steering wheel, steering angle to the horizon and etc were examined. Data analysis was conducted by statistical methods (SPSS-16 and x2 test) and the p-value of 0.05 was used as significant. Results: The results showed that there was a significant relationship between the slope of the pedals, the height of steering wheel, seat position, availability of the driver cab, steering angle, the use of driver back protector with the prevalence of musculoskeletal disorders and the spinal pain due to the driving (p<0.05). Conclusions: Recognition of many factors in design of equipment of driver cab to create the safe environment for drivers is necessary. Therefore, the condition around of driver in car should be identified and so design that driver feeling comfort and relax on duty

Identification and Classification of Risks and Potential Events by using Preliminary Hazard Analysis Method (PHA) in Kermanshah Oil Refinery

Background: humans are always trying to improve the lives and comfort, and in this way with the acquisition of materials, equipment, devices and technology as well as the additional and new risks exposure. Identification of these risks could have a role in reducing complications. PHA method implementation can help to identify and classify the risks and the events. Method: This cross - sectional study was conducted in Kermanshah Oil Refinery. The most important tools used in the study preliminary risk analysis, is risk checklist. In this regard, valuable resources are identified and listed, and then the acceptable risk levels and the scope of the assessment were defined. In the next phase, the system hazards were identification, and levels and numbers of risks were calculated. Results: This study examined 23 refinery units, and a total of 447 risks were identified. The results showed that unacceptable risk levels with 6.4% and the adverse risk levels with 49.22% was lowest and highest risk percent, respectively. The highest number of risk associated with the refining unit with 81 and the lowest was in the Electrical warehouse unit with 2 cases. Conclusion: The results of this study showed that were the most of risks identified in the adverse levels. To reduce risk level and improve safety, the use of appropriate methods and corrective measures to eliminate, reduce or control risks is essential

Ischemic preconditioning affects phosphosites and accentuates myocardial stunning while reducing infarction size in rats

Background and aimsIschemic preconditioning (IPC), i.e., brief periods of ischemia, protect the heart from subsequent prolonged ischemic injury, and reduces infarction size. Myocardial stunning refers to transient loss of contractility in the heart after myocardial ischemia that recovers without permanent damage. The relationship between IPC and myocardial stunning remains incompletely understood. This study aimed primarily to examine the effects of IPC on the relationship between ischemia duration, stunning, and infarct size in an ischemia-reperfusion injury model. Secondarily, this study aimed to examine to which extent the phosphoproteomic changes induced by IPC relate to myocardial contractile function.Methods and resultsRats were subjected to different durations of left anterior descending artery (LAD) occlusion, with or without preceding IPC. Echocardiograms were acquired to assess cardiac contraction in the affected myocardial segment. Infarction size was evaluated using triphenyl tetrazolium chloride staining. Phosphoproteomic analysis was performed in heart tissue from preconditioned and non-preconditioned animals. In contrast to rats without IPC, reversible akinesia was observed in a majority of the rats that were subjected to IPC and subsequently exposed to ischemia of 13.5 or 15 min of ischemia. Phosphoproteomic analysis revealed significant differential regulation of 786 phosphopeptides between IPC and non-IPC groups, with significant associations with the sarcomere, Z-disc, and actin binding.ConclusionIPC induces changes in phosphosites of proteins involved in myocardial contraction; and both accentuates post-ischemic myocardial stunning and reduces infarct size

Table3_Ischemic preconditioning affects phosphosites and accentuates myocardial stunning while reducing infarction size in rats.docx

Background and aimsIschemic preconditioning (IPC), i.e., brief periods of ischemia, protect the heart from subsequent prolonged ischemic injury, and reduces infarction size. Myocardial stunning refers to transient loss of contractility in the heart after myocardial ischemia that recovers without permanent damage. The relationship between IPC and myocardial stunning remains incompletely understood. This study aimed primarily to examine the effects of IPC on the relationship between ischemia duration, stunning, and infarct size in an ischemia-reperfusion injury model. Secondarily, this study aimed to examine to which extent the phosphoproteomic changes induced by IPC relate to myocardial contractile function.Methods and resultsRats were subjected to different durations of left anterior descending artery (LAD) occlusion, with or without preceding IPC. Echocardiograms were acquired to assess cardiac contraction in the affected myocardial segment. Infarction size was evaluated using triphenyl tetrazolium chloride staining. Phosphoproteomic analysis was performed in heart tissue from preconditioned and non-preconditioned animals. In contrast to rats without IPC, reversible akinesia was observed in a majority of the rats that were subjected to IPC and subsequently exposed to ischemia of 13.5 or 15 min of ischemia. Phosphoproteomic analysis revealed significant differential regulation of 786 phosphopeptides between IPC and non-IPC groups, with significant associations with the sarcomere, Z-disc, and actin binding.ConclusionIPC induces changes in phosphosites of proteins involved in myocardial contraction; and both accentuates post-ischemic myocardial stunning and reduces infarct size.</p

Table1_Ischemic preconditioning affects phosphosites and accentuates myocardial stunning while reducing infarction size in rats.docx

Background and aimsIschemic preconditioning (IPC), i.e., brief periods of ischemia, protect the heart from subsequent prolonged ischemic injury, and reduces infarction size. Myocardial stunning refers to transient loss of contractility in the heart after myocardial ischemia that recovers without permanent damage. The relationship between IPC and myocardial stunning remains incompletely understood. This study aimed primarily to examine the effects of IPC on the relationship between ischemia duration, stunning, and infarct size in an ischemia-reperfusion injury model. Secondarily, this study aimed to examine to which extent the phosphoproteomic changes induced by IPC relate to myocardial contractile function.Methods and resultsRats were subjected to different durations of left anterior descending artery (LAD) occlusion, with or without preceding IPC. Echocardiograms were acquired to assess cardiac contraction in the affected myocardial segment. Infarction size was evaluated using triphenyl tetrazolium chloride staining. Phosphoproteomic analysis was performed in heart tissue from preconditioned and non-preconditioned animals. In contrast to rats without IPC, reversible akinesia was observed in a majority of the rats that were subjected to IPC and subsequently exposed to ischemia of 13.5 or 15 min of ischemia. Phosphoproteomic analysis revealed significant differential regulation of 786 phosphopeptides between IPC and non-IPC groups, with significant associations with the sarcomere, Z-disc, and actin binding.ConclusionIPC induces changes in phosphosites of proteins involved in myocardial contraction; and both accentuates post-ischemic myocardial stunning and reduces infarct size.</p

Table2_Ischemic preconditioning affects phosphosites and accentuates myocardial stunning while reducing infarction size in rats.docx

Background and aimsIschemic preconditioning (IPC), i.e., brief periods of ischemia, protect the heart from subsequent prolonged ischemic injury, and reduces infarction size. Myocardial stunning refers to transient loss of contractility in the heart after myocardial ischemia that recovers without permanent damage. The relationship between IPC and myocardial stunning remains incompletely understood. This study aimed primarily to examine the effects of IPC on the relationship between ischemia duration, stunning, and infarct size in an ischemia-reperfusion injury model. Secondarily, this study aimed to examine to which extent the phosphoproteomic changes induced by IPC relate to myocardial contractile function.Methods and resultsRats were subjected to different durations of left anterior descending artery (LAD) occlusion, with or without preceding IPC. Echocardiograms were acquired to assess cardiac contraction in the affected myocardial segment. Infarction size was evaluated using triphenyl tetrazolium chloride staining. Phosphoproteomic analysis was performed in heart tissue from preconditioned and non-preconditioned animals. In contrast to rats without IPC, reversible akinesia was observed in a majority of the rats that were subjected to IPC and subsequently exposed to ischemia of 13.5 or 15 min of ischemia. Phosphoproteomic analysis revealed significant differential regulation of 786 phosphopeptides between IPC and non-IPC groups, with significant associations with the sarcomere, Z-disc, and actin binding.ConclusionIPC induces changes in phosphosites of proteins involved in myocardial contraction; and both accentuates post-ischemic myocardial stunning and reduces infarct size.</p