Nanoscale electrochemical patterning reveals the active sites for catechol oxidation at graphite surfaces

Graphite-based electrodes (graphite, graphene, and nanotubes) are used widely in electrochemistry, and there is a long-standing view that graphite step edges are needed to catalyze many reactions, with the basal surface considered to be inert. In the present work, this model was tested directly for the first time using scanning electrochemical cell microscopy reactive patterning and shown to be incorrect. For the electro-oxidation of dopamine as a model process, the reaction rate was measured at high spatial resolution across a surface of highly oriented pyrolytic graphite. Oxidation products left behind in a pattern defined by the scanned electrochemical cell served as surface-site markers, allowing the electrochemical activity to be correlated directly with the graphite structure on the nanoscale. This process produced tens of thousands of electrochemical measurements at different locations across the basal surface, unambiguously revealing it to be highly electrochemically active, with step edges providing no enhanced activity. This new model of graphite electrodes has significant implications for the design of carbon-based biosensors, and the results are additionally important for understanding electrochemical processes on related sp2-hybridized materials such as pristine graphene and nanotubes

RETIREES FROM PUBLIC SERVICE IN NIGERIA: A SURVEY

The proportion of the Nigeria’s population that is retired is large and growing, and the government face huge fiscal burdens because of promises it has made to provide income security (pension) to this set of people. Improving the adequacy and quality of pension is a priority for Nigerian government, because of the growing disenchantment by retirees over government delays to pay new improved pension schemes. The realization that effective policy and planning must take into account what pensioners want and are prepared to take is the impetus that the government is interested in meaningful life after retirement from public service. The paper aims at enriching our study course on planning for retirement, providing policy makers with reliable basis from the field that are useful for executive decisions, and to enrich would be retirees on what many retirees are experiencing and going through, to plan and save well during work life and to prepare for challenges ahead. Infact, life in retirement is not rosy and cosy for majority as pensioners face difficulties in getting their pays, arrears for months accumulated, government reluctance to implement the 148% increase and several other problems. In protecting the old and promoting economic growth, Nigeria needs to consider comprehensive pension reforms. The research team used direct (contingent valuation) surveys and ML –Censored Normal (Tobit) methods to estimate the number of retirees’ willingness to live meaningful life should the government pay them arrears and implement the increase package and other types of improvement. Clearly, the methodology produced some illuminating in sights into how to decide what level of service is appropriate for this segment of the society and how the improved services should be well implemented

Using cellular fitness to map the structure and function of a major facilitator superfamily effluxer.

The major facilitator superfamily (MFS) effluxers are prominent mediators of antimicrobial resistance. The biochemical characterization of MFS proteins is hindered by their complex membrane environment that makes in vitro biochemical analysis challenging. Since the physicochemical properties of proteins drive the fitness of an organism, we posed the question of whether we could reverse that relationship and derive meaningful biochemical parameters for a single protein simply from fitness changes it confers under varying strengths of selection. Here, we present a physiological model that uses cellular fitness as a proxy to predict the biochemical properties of the MFS tetracycline efflux pump, TetB, and a family of single amino acid variants. We determined two lumped biochemical parameters roughly describing Km and Vmax for TetB and variants. Including in vivo protein levels into our model allowed for more specified prediction of pump parameters relating to substrate binding affinity and pumping efficiency for TetB and variants. We further demonstrated the general utility of our model by solely using fitness to assay a library of tet(B) variants and estimate their biochemical properties

Enhanced photocatalytic degradation of azo dye using rare-earth metal doped TiO2 under visible light irradiation

Lanthanum doped TiO2 nanoparticles (La doped TiO2) have been prepared by a sol-gel process using TiO(C4H9)4 as raw material and are characterized using XRD, FT-IR, SEM-EDS, TEM and UV-DRS. The insertion of La ion in TiO2 lattice has been confirmed by SEM-EDS and XRD data. TEM studies have confirmed that La ions are uniformly doped over TiO2 lattice. The band gap level of La doped TiO2 is decreased to 2.92 eV with a red shift due to charge transfer reaction which is confirmed by UV-DRS. The photocatalytic activities of the synthesized nanoparticles are evaluated for the degradation of Congo red dye (20 ppm) in an aqueous solution with La doped TiO2 (0.25 g) at pH= 6.3, under solar light irradiation. The photocatalytic results confirmed that the La doped TiO2 show good photocatalytic activity and can be considered as a promising photocatalyst for the degradation of organic pollutants in water. Due to the stability of La doped TiO2 nanoparticles, it could be reused for more than five cycles reaching 100% degradation efficiency

A study to evaluate the effectiveness of stretching exercise in reduction of low back pain among staff nurses working in a selected hospitals, Kanyakumari district

Low back pain is neither a disease nor a diagnostic entity of any sort. The term refers to pain of variable duration in an area of the anatomy afflicted so often that it is has become a paradigm of responses to external and internal stimuli. Statement of the problem A study to evaluate the effectiveness of stretching exercise in reduction of low back pain among staff nurses working in a selected hospitals, Kanyakumari district. Objectives of the Study 1) To assess the pre test and post test level of low back pain among staff nurses in experimental group and control group. 2) To find out the effectiveness of stretching exercise on low back pain among staff nurses in experimental and control group. 3) To associate the pre test level of low back pain among staff nurses in experimental and control group with their selected demographic variables.(Age, Sex, Educational status, unit, marital status, clinical experience) The investigator adopted Callista Roy’s Adaptation Model (1984) as the conceptual frame work for this study. Quasi experimental research design Was used and the formal consent was obtained from P.S. Medical Trust Hospital Thalakkulam and the investigator selected 60 samples using Purposive sampling technique were selected, as a samples both in experimental group and control group . Descriptive and inferential statistics were used to analyze the data. Analysis of demographic variables was done in terms of frequency and percentage distribution. Comparison of post test level of low back pain between the experimental group and control group was analyzed by ‘t’ test which is an inferential statistical analysis. Association of pre test level of low back pain in the experimental group and control group with demographic variables was analyzed by using chi-square test. The study revealed that among experimental group the mean pre-test score was 27.3 with standard deviation 7.29. The mean post-test was 16.6 with standard deviation 5.37. The mean difference was 10.7. The obtained ‘t’ test value was 17.63,which was significant at p< 0.05 level. Hence it was inferred that stretching exercise was highly effective in reducing of low back pain among staff nurses with low back pain

Effectiveness of structured teaching programme on knowledge regarding vaginitis and its prevention among adolescent girlsin selected higher secondary school at Madurai

The study on “Effectiveness of Structured Teaching Programme on Knowledge regarding Vaginitis and its Prevention among adolescent Girls in selected Higher secondary school at Madurai was undertaken by Reg.no.30111081during the year 2012-2013 in partial fulfilment of the requirement for the degree of Master of Science in Nursing at RASS Academy College of Nursing, Poovanthi which is affiliated to The Tamilnadu Dr.M.G.R. Medical University, Chennai. OBJECTIVES: To assess the level of knowledge of adolescent girls regarding vaginitis and its prevention before structured teaching programme. Evaluate the effectiveness of Structured Teaching Programme (STP) on vaginitis and its prevention in terms of gain in knowledge score using a structured knowledge questionnaire. Compare the pre test and post test knowledge scores among adolescent girls regarding vaginitis and its prevention. Determine the association between the level of knowledge score before structured teaching programme and selected demographic variables. Conceptual frame work: The study was based on modified Imogene king’s goal theory. Design: Evaluatory approach and pre-experimental design was adopted for this study. Setting: The study was conducted at kakaipadiyar girls higher secondary school at Madurai district. Sample size: The sample size was 60 higher secondary school girls. Sampling technique: The purposive sampling technique was used to select the adolescent girls. Methods of data collection procedure: Data were collected from adolescent girls to assess level of knowledge by using structured tool before and after structured teaching programme. After administration of structured teaching programme the level of knowledge is assessed. The collected data were tabulated and analyzed by descriptive and inferential statistics. RESULTS: Structured teaching programme is effective of adolescent girls according to level of knowledge before and after the manipulation in which (41.67%) of the samples had showed inadequate level of knowledge in the pretest. In contrast, (70%) of the samples experienced adequate level of knowledge in the posttest. The mean post test knowledge score (17.62) was greater than the mean pretest level of knowledge score (9.52). The obtained t-value (14.33) was statistically highly significant at 0.05 levels. The mean difference between pretest score and post test score of 8.1 was significant at 5% level as the (*p < 0.05). CONCLUSION: The association of pre and post test level of knowledge after the structured teaching programme was adequate

A Comparison of Corrosion Behavior of Copper and Its Alloy in Pongamia pinnata Oil at Different Conditions

Vegetable oils are promising substitutes for petrodiesel as they can be produced from numerous oil seed crops that can be cultivated anywhere and have high energy contents, exhibiting clean combustion behavior with zero CO2 emission and negligible SO2 generation. The impact of biofuel on the corrosion of various industrial metals is a challenge for using biofuel as automotive fuel. Fuel comes in contact with a wide variety of metallic materials under different temperatures, velocities, and loads thereby causing corrosion during storage and flow of fuel. Hence, the present investigation compares the corrosion rates of copper and brass in Pongamia pinnata oil (O100), 3% NaCl, and oil blend with NaCl (O99) obtained by static immersion test and using rotating cage. The corrosivity and conductivity of the test media are positively correlated. This study suggested that the corrosivity of copper is higher than brass in Pongamia pinnata oil (PO)

Stairstep Health Initiative. Evaluation Report FY 2002-2003.

Prepared for Stairstep Fondation, Inc. with funding from a CURA Communiversity Personnel Grant

Electrochemistry of Fe3+/2+ at highly oriented pyrolytic graphite (HOPG) electrodes : kinetics, identification of major electroactive sites and time effects on the response

The electrochemistry of the Fe3+/2+ redox couple has been studied on highly oriented pyrolytic graphite (HOPG) samples that differ in step edge density by 2 orders of magnitude to elucidate the effect of surface structure on the electron transfer (ET) kinetics. Macroscopic cyclic voltammetry measurements in a droplet-cell arrangement, highlight that the Fe3+/2+ process is characterised by slow ET kinetics on HOPG and that step edge coverage has little effect on the electrochemistry of Fe3+/2+. A standard heterogeneous ET rate constant of ~5 × 10-5 cm s-1 for freshly cleaved HOPG was derived from simulation of the experimental results, which fell into the range of the values reported for metal eletrodes, e.g. platinum and gold, despite the remarkable difference in density of electronic states (DOS) between HOPG and metal electrodes. This provides further evidence that outer-sphere redox processes on metal and sp2 carbon electrodes appear to be adiabatic. Complementary surface electroactivity mapping of HOPG, using scanning electrochemical cell microscopy, reveal the basal plane to be the predominant site for the Fe3+/2+ redox process. It is found that time after cleavage of the HOPG surface has an impact on the surface wettability (and surface contamination), as determined by contact angle measurements, and that this leads to a slow deterioration of the kinetics. These studies further confirm the importance of understanding and evaluating surface structure and history effects in HOPG electrochemistry, and how high resolution measurements, coupled with macroscopic studies provide a holistic view of electrochemical processes