382 research outputs found
Simultaneous estimation of heat flux and heat transfer coefficient in irregular geometries made of functionally graded materials
A numerical inverse analysis based on explicit sensitivity coefficients is developed for the simultaneous estimation of heat flux and heat transfer coefficient imposed on different parts of boundary of a general irregular heat conducting body made of functionally graded materials with spatially varying thermal conductivity. It is assumed that the thermal conductivity varies exponentially with position in the body. The body considered in this study is an eccentric hollow cylinder. The heat flux is applied on the cylinder inner surface and the heat is dissipated to the surroundings through the outer surface. The numerical method used in this study consists of three steps: 1) to apply a boundary-fitted grid generation (elliptic) method to generate grid over eccentric hollow cylinder (an irregular shape) and then solve for the steady-state heat conduction equation with variable thermal conductivity to compute the temperature values in the cylinder, 2) to propose a new explicit sensitivity analysis scheme used in inverse analysis, and 3) to apply a gradient-based optimization method (in this study, conjugate gradient method) to minimize the mismatch between the computed temperature on the outer surface of the cylinder and simulated measured temperature distribution. The inverse analysis presented here is not involved with an adjoint equation and all the sensitivity coefficients can be computed in only one direct solution, without the need for the solution of the adjoint equation. The accuracy, efficiency, and robustness of the developed inverse analysis are demonstrated through presenting a test case with different initial guesses
Effectiveness of smart phone application use as continuing medical education method in pediatric oral health care: a randomized trial
Background
Continuing education aims at assisting physicians to maintain competency and expose them to emerging issues in their field. Over the last decade, approaches to the delivery of educational content have changed dramatically as medical education at all levels is now benefitting from the use of web-based content and applications for mobile devices. The aim of the present study is to investigate through a randomized trial the effectiveness of a smart phone application to increase public health service physicians’ (PHS physicians) knowledge regarding pediatric oral health care.
Method
Five of all seven DHCs (District Health Center) in Tehran, which were under the supervision of Tehran University of Medical Sciences and Iran University of Medical Sciences, were selected for our study. Physicians of one DHC had participated in a pilot study. All PHS physicians in the other four centers were invited to the current study on a voluntary basis (n = 107). They completed a self-administered questionnaire regarding their knowledge, attitudes, practice in pediatric dentistry, and background. PHS physicians were assigned randomly to intervention and control groups; those in the intervention group, received a newly designed evidence-based smartphone application, and those in the control group received a booklet, a CME seminar, and a pamphlet. A post-intervention survey was administered 4 months later and t-test and repeated measures ANCOVA (Analysis of Covariance) were performed to measure the difference in the PHS physicians’ knowledge, attitude and practice.
Results
In both groups, the mean knowledge scores were significantly higher (p-Value < 0.001) in post-intervention data compared to those at baseline. Similar results existed in attitude and practice scores. Although the scores in knowledge in the intervention group indicating potentially greater improvement when compared to those of the control group, the differences between the two groups were not statistically significant (dif: 0.84, 95% CI − 0.35 to 2.02).
Conclusion
In the light of the limitations of the present study, smart phone applications could improve knowledge, attitude and practice in physicians although this method was not superior to the conventional method of CME
Use of an audit with feedback implementation strategy to promote medication error reporting by nurses
Aims and objectivesTo outline the development and effect of an audit with feedback implementation strategy that intended to increase the rate of voluntary medication error reporting by nurses.BackgroundMedication errors are a serious global health issue. Audit with feedback is a widely used implementation strategy that has potential to modify nurses’ reporting behaviour and improve medication error reporting rates.DesignQuasi‐experimental implementation study (fulfilling the TIDieR checklist) with two pairs of matched wards at a private hospital in Australia was conducted from March 2015–September 2016. One ward from each pair was randomised to either the intervention or control group.MethodNurses within intervention wards received audit with feedback on a quarterly basis over a 12‐month implementation period. Control wards underwent quarterly audits only (without feedback). Feedback consisted of a one‐page infographic poster, with content based on medication error data obtained from audits and the hospitals’ risk management system (RiskMan). The primary outcome—rate of medication errors reported per month—was determined in both groups at pre‐implementation, implementation and postimplementation phases. Differences between groups were compared using generalised linear mixed models with Poisson distribution and log link.ResultsA nonsignificant intervention effect was found for rate of medication errors reported per month. Interestingly, when combining data from both groups, a significant increasing time trend was observed for medication errors reported per month across pre‐implementation and implementation phases (80% increase).ConclusionsThe audit with feedback strategy developed in the present study did not effectively influence the voluntary reporting of medication errors by nurses.Relevance to clinical practiceDespite the lack of intervention effects, the use of a published checklist to optimise the reporting quality of this study will contribute to the field by furthering the understanding of how to enhance audit with feedback implementation strategies for nurses.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163422/2/jocn15447.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163422/1/jocn15447_am.pd
A poisson regression approach for modelling spatial autocorrelation between geographically referenced observations
Abstract Background Analytic methods commonly used in epidemiology do not account for spatial correlation between observations. In regression analyses, omission of that autocorrelation can bias parameter estimates and yield incorrect standard error estimates. Methods We used age standardised incidence ratios (SIRs) of esophageal cancer (EC) from the Babol cancer registry from 2001 to 2005, and extracted socioeconomic indices from the Statistical Centre of Iran. The following models for SIR were used: (1) Poisson regression with agglomeration-specific nonspatial random effects; (2) Poisson regression with agglomeration-specific spatial random effects. Distance-based and neighbourhood-based autocorrelation structures were used for defining the spatial random effects and a pseudolikelihood approach was applied to estimate model parameters. The Bayesian information criterion (BIC), Akaike's information criterion (AIC) and adjusted pseudo R2, were used for model comparison. Results A Gaussian semivariogram with an effective range of 225 km best fit spatial autocorrelation in agglomeration-level EC incidence. The Moran's I index was greater than its expected value indicating systematic geographical clustering of EC. The distance-based and neighbourhood-based Poisson regression estimates were generally similar. When residual spatial dependence was modelled, point and interval estimates of covariate effects were different to those obtained from the nonspatial Poisson model. Conclusions The spatial pattern evident in the EC SIR and the observation that point estimates and standard errors differed depending on the modelling approach indicate the importance of accounting for residual spatial correlation in analyses of EC incidence in the Caspian region of Iran. Our results also illustrate that spatial smoothing must be applied with care.</p
Applications of SSAFT EOS for determination of the solubilities of solid compounds in supercritical CO2.
Using statistical thermodynamics such as Simplified SAFT equation of state (SSAFTEoS) for estimating phase equilibrium and fluid properties of different materials have been used widely. SSAFT EoS has been developed for associative and non-associative compounds. At high pressure inter molecular forces are very important, on the other hand, in spite of the fact that SSAFT EoS has strength theoretical foundation, it can predict the behavior of high pressure systems. In this research, four solid solubility of benzoic acid, naphthalene, pyrene and Phenanthrene in supercritical carbon dioxide have been studied, SSAFT EoS has been used for modeling. At the end the results have been compared with experimental data. The highest and the absolute average deviation error (AAPD), for carbon dioxide - Phenanthrene and benzoic acid - carbon dioxide systems have been reported 2.22 and 4.43 respectively.Keywords: SSAFT EoS; Supercritical carbon dioxide; Solid compounds; Solubility
Serum sclerostin is associated with recurrent kidney stone formation independent of hypercalciuria
Kidney stones are frequent in industrialized countries with a lifetime risk of 10 to 15%. A high percentage of individuals experience recurrence. Calcium-containing stones account for more than 80% of kidney stones. Diet, environmental factors, behavior, and genetic variants contribute to the development of kidney stones. Osteocytes excrete the 21 kDa glycoprotein sclerostin, which inhibits bone formation by osteoblasts. Animal data suggests that sclerostin might directly or indirectly regulate calcium excretion via the kidney. As hypercalciuria is one of the most relevant risk factors for kidney stones, sclerostin might possess pathogenic relevance in nephrolithiasis.
We performed a prospective cross-sectional observational controlled study in 150 recurrent kidney stone formers (rKSF) to analyse the association of sclerostin with known stone risk factors and important modulators of calcium-phosphate metabolism. Serum sclerostin levels were determined at the first visit. As controls, we used 388 non-stone formers from a large Swiss epidemiological cohort.
Sclerostin was mildly increased in rKSF in comparison to controls. This finding was more pronounced in women compared to men. Logistic regression indicated an association of serum sclerostin with rKSF status. In hypercalciuric individuals, sclerostin levels were not different from normocalciuric patients. In Spearman correlation analysis we found a positive correlation between sclerostin, age, and BMI and a negative correlation with eGFR. There was a weak correlation with iPTH and intact FGF 23. In contrast, serum sclerostin levels were not associated with 25-OH Vitamin D3, 1,25-dihydroxy-Vitamin D3, urinary calcium and phosphate or other urinary lithogenic risk factors.
This is the first prospective controlled study investigating serum sclerostin in rKSF. Sclerostin levels were increased in rKSF independent of hypercalciuria and significantly associated with the status as rKSF. It appears that mechanisms other than hypercalciuria may be involved and thus further studies are required to elucidate underlying pathways
The Iranian Study of Opium and Cancer (IROPICAN): Rationale, design, and initial findings
Background: The International Agency for Research on Cancer (IARC) recently classified opium use as a Group 1 carcinogen. However, much remains to be studied on the relation between opium and cancer. We designed the Iranian Opium and Cancer (IROPICAN) study to further investigate the association of opium use and cancers of the head and neck, bladder, lung, and colon and rectum. In this paper, we describe the rationale, design, and some initial results of the IROPICAN Study. Methods: The IROPICAN is a multi-center case-control study conducted in 10 provinces of Iran. The cases were all histologically confirmed and the controls were selected from hospital visitors who were free of cancer, were not family members or friends of the cancer patients, and were visiting the hospital for reasons other than their own ailment. The questionnaires included detailed questions on opium use (including age at initiation, duration, frequency, typical amount, and route), and potential confounders, such as tobacco use (e.g., cigarettes, nass and water-pipe), and dietary factors. Biological samples, including blood and saliva, were also collected. Results: The validation and pilot phases showed reasonably good validity, with sensitivities of 70% and 69% for the cases and controls, respectively, in reporting opium use. The results also showed excellent reliability, with intra-class correlation coefficients of 0.96 for ever opium use and 0.88 (95% CI: 0.80, 0.92) for regular opium use. In the main phase, we recruited 3299 cancer cases (99% response rate) and 3477 hospital visitor controls (89% response rate). The proportion of ever-use of opium was 40% among cases and 18% among controls. Conclusion: The IROPICAN study will serve as a major resource in studies addressing the effect of opium on risk of cancers of the head and neck, bladder, lung, and colon and rectum
Ectopic Pregnancy in the Cervix: A Case Report
Cervical pregnancy is an extremely rare condition with potential grave consequences if not diagnosed and treated early enough. We present a case and an ultrasound image of early cervical ectopic pregnancy with a history of two previous cesarean sections who was successfully treated with suction curettage
ASPREE-D: Aspirin for the prevention of depression in the elderly
Copyright © International Psychogeriatric Association 2016. Background:: Not only is depression associated with increased inflammation but inflammation is a risk factor for the genesis of depression. Many of the environmental risk factors for depression are transduced through inflammatory signaling. Anti-inflammatory agents show promise for the management of depression in preclinical, epidemiological, and early clinical studies. This opens the door to the potential for anti-inflammatory agents to treat and prevent depression. There are no evidence-based pharmacotherapies for depression prevention. Method:: ASPREE-D, aspirin in the prevention of depression in the elderly, is a sub study of ASPREE, which explores the potential of aspirin to prevent a range of inflammation related disorders in the elderly. With a sample size of 19,114, and a duration of 5 years, this placebo controlled study will be one of the largest randomized controlled trials in psychiatry and will provide definitive evidence on the ability of aspirin to prevent depression. Results:: This paper presents the rationale for the study and presents a summary of the study design. Conclusions:: ASPREE-D may not only define novel therapy but will provide mechanistic proof of concept of the role of inflammation in depression
Nothing will ever be as before. Reflections on the COVID-19 epidemics by nephrologists in eleven countries
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