Tribo-corrosion of steel in artificial saliva

Stainless steel is widely used as dental implant. However, there has been little work on the micro-abrasion of such materials in laboratory simulated oral environments, where abrasion, sliding wear can interact simultaneously. In this study, the effects of applied load, and exposure time were evaluated for a 316 stainless steel in a laboratory simulated artificial saliva. Polarization curves showed an enhancement of corrosion current density with increases in applied load. Wear maps were produced showing low wear safety regimes at intermediate loads and exposure times. Possible reasons for such trends are interpreted in terms of the ability of the passive film in providing resistance against third body particle impact and the concentration of particles in the contact at higher loads

Double Relaxation via AdS/CFT

We exploit the AdS/CFT correspondence to investigate thermalization in an N=2 strongly coupled gauge theory including massless fundamental matter (quark). More precisely, we consider the response of a zero temperature state of the gauge theory under variation of an external electric field leading to a time-dependent current. The holographic dual of the above set-up is given by introducing a time-dependent electric field on the probe D7-brane embedded in an AdS_5 X S^5 background. In the dual gravity theory, due to a time-dependent electric field an apparent horizon forms on the brane which, according to AdS/CFT dictionary, is the counterpart of the thermalization process in the gauge theory. We classify different functions for time-dependent electric field and study their effect on the apparent horizon formation. In the case of pulse functions where the electric field varies from zero to zero, apart from non-equilibrium phase, we observe that two apparent horizons form on the brane. On the gauge theory side, it means that the state of the gauge theory experiences two different temperatures during the time evolution.Comment: 28 pages, 13 figures, published versio

Predictors of Postpartum Depression in an Iranian Population, 2006

Background: Postpartum depression has serious complications. There are various risk factors for postpartum depression and in some cases these are controversial. Objectives: This study tested the prevalence of postpartum depression and its related factors in Kashan, Iran, in 2006. Patients and Methods: In this cross-sectional study, 460 women referred to Kashan’s health centers, during the second and third months after childbirth, were enrolled. The Beck Depression Inventory was used to make a diagnosis of depression. Other variables such as; type of delivery, satisfaction with husband, and demographic features were also assessed. Data were analyzed by chi-square, independent t-test and regression analysis, using SPSS 16 software. Results: The prevalence of severe and moderate depression was 28.9%. Our findings did not reveal any significant relationship between; type of delivery, unwanted pregnancy, gender of neonate, duration of marriage and gravidity with postpartum depression (P > 0.05). The stepwise regression analysis showed that depression made a significant model with; satisfaction with husband, age and education of mother. Conclusions: Satisfaction with husband, age and education of mother are the important risk factors for postpartum depression

Triumph of hope over experience: learning from interventions to reduce avoidable hospital admissions identified through an Academic Health and Social Care Network.

BACKGROUND: Internationally health services are facing increasing demands due to new and more expensive health technologies and treatments, coupled with the needs of an ageing population. Reducing avoidable use of expensive secondary care services, especially high cost admissions where no procedure is carried out, has become a focus for the commissioners of healthcare. METHOD: We set out to identify, evaluate and share learning about interventions to reduce avoidable hospital admission across a regional Academic Health and Social Care Network (AHSN). We conducted a service evaluation identifying initiatives that had taken place across the AHSN. This comprised a literature review, case studies, and two workshops. RESULTS: We identified three types of intervention: pre-hospital; within the emergency department (ED); and post-admission evaluation of appropriateness. Pre-hospital interventions included the use of predictive modelling tools (PARR - Patients at risk of readmission and ACG - Adjusted Clinical Groups) sometimes supported by community matrons or virtual wards. GP-advisers and outreach nurses were employed within the ED. The principal post-hoc interventions were the audit of records in primary care or the application of the Appropriateness Evaluation Protocol (AEP) within the admission ward. Overall there was a shortage of independent evaluation and limited evidence that each intervention had an impact on rates of admission. CONCLUSIONS: Despite the frequency and cost of emergency admission there has been little independent evaluation of interventions to reduce avoidable admission. Commissioners of healthcare should consider interventions at all stages of the admission pathway, including regular audit, to ensure admission thresholds don't change

Development of an efficient procedure for the preconcentration of copper(II) after solid phase extraction on modified sawdust

A sensitive and selective preconcentration method has been developed for copper(II) using modified sawdust as an adsorbent. Sawdust was chemically modified with diethylenetriamine. Copper as CuCl42- was retained by the adsorbent in the column, eluted by nitric acid and subsequently determined by flame atomic absorption spectrometer. The effect of pH, chloride concentration, volume of the sample and diverse ions on the recovery of the analyte was investigated. A preconcentration factor of 250 was achieved using optimum conditions. The calibration graph was linear in the range 1-150 ng mL-1 copper in the initial solution. The detection limit (3Sb) was 0.2 ng mL-1 and the relative standard deviations were 2.7 and 1.2% for 5 and 50 ng mL-1 respectively (n = 10). It was revealed that after ten cycles of adsorption and desorption, the adsorbent retained its promising adsorption ability. The method was successfully applied to the determination of copper(II) in different water samples. Obtained results showed that the developed method is relatively simple, accurate, sensitive and selective. KEY WORDS: Copper(II), Preconcentration, Modified sawdust Bull. Chem. Soc. Ethiop. 2014, 28(3), 321-328.DOI: http://dx.doi.org/10.4314/bcse.v28i3.