52 research outputs found

    A New Hybrid Robust Fault Detection of Switching Systems by Combination of Observer and Bond Graph Method

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    In this paper, the problem of robust Fault Detection (FD) for continuous time switched system is tackled using a hybrid approach by combination of a switching observer and Bond Graph (BG) method. The main criteria of an FD system including the fault sensitivity and disturbance attenuation level in the presence of parametric uncertainties are considered in the proposed FD system. In the first stage, an optimal switching observer based on state space representation of the BG model is designed in which simultaneous fault sensitivity and disturbance attenuation level are satisfied using H=H1 index. In the second stage, the Global Analytical Redundancy Relations (GARRs) of the switching system are derived based on the output estimation error of the observer, which is called Error-based Global Analytical Redundancy Relations (EGARRs). The parametric uncertainties are included in the EGARRs, which define the adaptive thresholds on the residuals. A constant term due to the effect of disturbance is also considered in the thresholds. In fact, a two-stage FD system is proposed wherein some criteria may be considered in each stage. The efficiency of the proposed method is shown for a two-tank system

    Antibacterial Effects of Chitosan, Formocresol and CMCP as Pulpectomy Medicament on Enterococcus ‎faecalis, Staphylococcus aureus and Streptococcus ‎mutans

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    Introduction: During pulpectomy of primary teeth, cytotoxic medicaments such as formocresol or camphor mono-chlorophenol (CMCP) are used as medicaments. For the first time it is theorized that chitosan can substitute these traditional materials used in pulpectomy of infectious primary teeth. Methods and Materials: This preliminary in vitro study consisted of two separate phases (n=75), each of which assessed the antibacterial effects of chitosan versus formocresol and CMCP and positive/negative controls (n=15) on three bacteria types [Enterococcus ‎faecalis, Staphylococcus aureus, Streptococcus ‎mutans, (n=5 per subgroup)]. Phases 1 and 2 concerned respectively with 1- and 7-day effects of these materials. Bacteria were cultured and injected into sterilized canals and colonies were counted. Medicaments were applied and colonies were re-counted after 1 day of treatment (phase 1). Specimens were re-sterilized and re-randomized, and used for phase 2, in which the same procedures were performed for a 7-day period. Effects of agents on bacteria were analyzed statistically (Kruskal-Wallis α=0.05 and Mann-Whitney α=0.017). Results: Treatments reduced bacterial count either after 1 or 7 days (P=0.000). Their effects on different bacteria types were not significant either after 1 or 7 days (P>0.48). Antibacterial efficacies of treatments (indicated by colony reduction) were significantly different, after 7 days (P=0.045). Antibacterial efficacy of chitosan was similar to that of formocresol or CMCP, in both phases [either after 1 or 7 days of treatment (P>0.017). Formocresol and CMCP had similar efficacies in either phase (P>0.017). Conclusions: This preliminary study confirmed the appropriate antibacterial efficacy of chitosan as a medicament in pulpectomy of infectious primary teeth.Keywords: Antibacterial Agents; Camphor Mono-Chlorophenol; Chitosan; CMCP; Enterococcus ‎faecalis; Formocresol; Medicament; Pulpectomy; Staphylococcus aureus; Streptococcus ‎mutan

    The 12-item medical outcomes study short form health survey version 2.0 (SF-12v2): a population-based validation study from Tehran, Iran

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    <p>Abstract</p> <p>Background</p> <p>The SF-12v2 is the improved version of the SF-12v1. This study aimed to validate the SF-12v2 in Iran.</p> <p>Methods</p> <p>A random sample of the general population aged 18 years and over living in Tehran, Iran completed the instrument. Reliability was estimated using internal consistency and validity was assessed using known-groups comparison and convergent validity. In addition the factor structure of the questionnaire was extracted by performing both exploratory and confirmatory factor analyses (EFA and CFA).</p> <p>Results</p> <p>In all, 3685 individuals were studied (1887male and 1798 female). Internal consistency for both summary measures was satisfactory. Cronbach's α for the Physical Component Summary (PCS-12) was 0.87 and for the Mental Component Summary (MCS-12) it was 0.82. Known-groups comparison showed that the SF-12v2 discriminated well between men and women and those who differed in age and educational status (P < 0.05). Furthermore, as hypothesized the physical functioning, role physical, bodily pain and general health subscales correlated higher with the PCS-12, while the vitality, social functioning, role emotional and mental health subscales correlated higher with the MCS-12. Finally the exploratory factor analysis indicated a two-factor structure (physical and mental health) that jointly accounted for 59.9% of the variance. The confirmatory factory analysis also indicated a good fit to the data for the two-latent structure (physical and mental health).</p> <p>Conclusion</p> <p>Although the findings could not be generalized to the Iranian population, overall the findings suggest that the SF-12v2 is a reliable and valid measure of health related quality of life among Iranians and now could be used in future health outcome studies. However, further studies are recommended to establish its stability, responsiveness to change, and concurrent validity for this health survey in Iran.</p

    The effect of heparin after primary percutaneous coronary intervention on short-term clinical outcomes in patients with ST-segment elevation myocardial infarction

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    Background: Doing percutaneous coronary intervention (PCI) in the first hours of myocardial infraction (MI) is effective in re-establishment of blood flow. Anticoagulation treatment should be prescribed in patients undergoing PCI to decrease the side effects of ischemia. The aim of this study is to determine the effect of heparin prescription after PCI on short-term clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI). Materials: This randomized clinical trial study was conducted at Imam Ali cardiovascular center at Kermanshah university of medical science (KUMS), Iran. Between April 2019 to October 2019, 400 patients with STEMI which candidate to PCI were enrolled. Patients randomly divided in two groups: intervention group (received 5,000 units of heparin after PCI until first 24 hours, every 6 hours) and control group (did not receive heparin). Data were collected using a checklist developed based on the study's aims. Differences between groups were assessed using independent t-tests and chi-square (or Fisher exact tests).Result: Observed that, mean prothrombin time (PT) (13.30±1.60 vs. 12.21±1.15, p<0.001) and partial thromboplastin time (PTT) (35.30±3.08 vs. 34.41±3.01, p=0.003) were significantly higher in intervention group compared to control group. Thrombolysis in myocardial infarction (TIMI) flow grade 0/1 after primary PCI was significantly more frequently in control group (5.5% vs. 1.0%, p=0.034). The mean of ejection fraction (EF) after PCI (47.58±7.12 vs. 45.15±6.98, p<0.001) was significantly higher in intervention group. Intervention group had a statistically significant shorter length of hospital stay (4.71±1.03 vs. 6.12±1.10, p<0.001). There was higher incidence of re-vascularization (0% vs. 3.0%; p=0.013) and re-MI (0% vs. 2.5%; p=0.024) in the control group.Conclusion: Performing primary PCI with receiving heparin led to improve TIMI flow and consequently better EF. Receiving heparin is associated with lower risk of re-MI and re-vascularization

    Global burden of chronic respiratory diseases and risk factors, 1990–2019: an update from the Global Burden of Disease Study 2019

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    Background: Updated data on chronic respiratory diseases (CRDs) are vital in their prevention, control, and treatment in the path to achieving the third UN Sustainable Development Goals (SDGs), a one-third reduction in premature mortality from non-communicable diseases by 2030. We provided global, regional, and national estimates of the burden of CRDs and their attributable risks from 1990 to 2019. Methods: Using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, we estimated mortality, years lived with disability, years of life lost, disability-adjusted life years (DALYs), prevalence, and incidence of CRDs, i.e. chronic obstructive pulmonary disease (COPD), asthma, pneumoconiosis, interstitial lung disease and pulmonary sarcoidosis, and other CRDs, from 1990 to 2019 by sex, age, region, and Socio-demographic Index (SDI) in 204 countries and territories. Deaths and DALYs from CRDs attributable to each risk factor were estimated according to relative risks, risk exposure, and the theoretical minimum risk exposure level input. Findings: In 2019, CRDs were the third leading cause of death responsible for 4.0 million deaths (95% uncertainty interval 3.6–4.3) with a prevalence of 454.6 million cases (417.4–499.1) globally. While the total deaths and prevalence of CRDs have increased by 28.5% and 39.8%, the age-standardised rates have dropped by 41.7% and 16.9% from 1990 to 2019, respectively. COPD, with 212.3 million (200.4–225.1) prevalent cases, was the primary cause of deaths from CRDs, accounting for 3.3 million (2.9–3.6) deaths. With 262.4 million (224.1–309.5) prevalent cases, asthma had the highest prevalence among CRDs. The age-standardised rates of all burden measures of COPD, asthma, and pneumoconiosis have reduced globally from 1990 to 2019. Nevertheless, the age-standardised rates of incidence and prevalence of interstitial lung disease and pulmonary sarcoidosis have increased throughout this period. Low- and low-middle SDI countries had the highest age-standardised death and DALYs rates while the high SDI quintile had the highest prevalence rate of CRDs. The highest deaths and DALYs from CRDs were attributed to smoking globally, followed by air pollution and occupational risks. Non-optimal temperature and high body-mass index were additional risk factors for COPD and asthma, respectively. Interpretation: Albeit the age-standardised prevalence, death, and DALYs rates of CRDs have decreased, they still cause a substantial burden and deaths worldwide. The high death and DALYs rates in low and low-middle SDI countries highlights the urgent need for improved preventive, diagnostic, and therapeutic measures. Global strategies for tobacco control, enhancing air quality, reducing occupational hazards, and fostering clean cooking fuels are crucial steps in reducing the burden of CRDs, especially in low- and lower-middle income countries

    The global burden of cancer attributable to risk factors, 2010-19 : a systematic analysis for the Global Burden of Disease Study 2019

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    Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% [47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% [32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% [27.9-42.8] and 33.3% [25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe

    An Investigation of Optimum Miscible Gas Flooding Scenario: A Case Study of an Iranian Carbonates Formation

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    Gas injection into carbonate formations is one of the most important activities to protect oil reserves that can guarantee a steady production. On-time injection of enough gas can result in the recovery of billions barrels of oil. In addition, it can preserve a huge amount of gas for the next generations. If the reservoir depth is shallow, or the reservoir fluid has a little amount of intermediate components, the flooding of rich gases is highly recommended. In the designing of a miscible injection process, firstly the minimum miscibility pressure should be measured or determined analytically. In this study, first the PVTi software is implemented to evaluate the miscibility of different injected gas, including carbon dioxide, nitrogen, methane, and different proportion of hydrocarbon gases. Subsequently, E-300 software is used to predict the recovery of the gas injection into the formation under study from one of the Iranian carbonate onshore fields. The investigation of the optimum injection rate as well as finding the proper layer of injection is investigated in details. The results show that the CO2 flooding after a long natural production period result in higher efficiency than the miscible injection of methane at the early stage of production

    Fuzzy Trust Aggregation And Personalized Trust Inference In Virtual Social Networks

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    Virtual marketplaces on the Web provide people with great facilities to buy and sell goods similar to conventional markets. In traditional business, reputation is subjectively built for known persons and companies as the deals are made in the course of time. As it is important to do business with trustful individuals and companies, there is a need to survive the reputation concept in virtual markets. Auction sites generally employ reputation systems based on feedbacks that provide a global view to a cyber dealer. In contrast to global trust, people usually infer their personal trust about someone whose reputation is completely or partially unknown by asking their trusted friends. Personal reputation is what makes a person trusted for some people and untrusted for others. There should be a facility for users in a virtual market to specify how much they trust a friend and also a mechanism that infers the trust of a user to another user who is not directly a friend of her. There are two main issues that should be addressed in trust inference. First, the trust modeling and aggregation problem needs to be challenged. Second, algorithms should be introduced to find and select the best paths among the existing trust paths from a source to a sink. First, as trust to a person can be stated more naturally using linguistic expressions, this work suggests employing linguistic terms for trust specification. To this end, corresponding fuzzy sets are defined for trust linguistic terms and a fuzzy trust aggregation method is also proposed. Comparing the fuzzy aggregation method to the existing aggregation methods shows superiority of fuzzy approach especially at aggregating contradictory information. Second, this paper proposes an incremental trust inference algorithm. The results show improvement in preciseness of inference for the proposed inference algorithm over the existing and recently proposed algorithm named TidalTrust
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