103 research outputs found
A Review In Preparation of Electronic Ink for Electrophoretic Displays
Electrophoretic displays attracted a lot of attention recently due to its low cost, low weight, low power consumption and reliability. Based on these characteristics, they are going to replace the conventional paper. Electrophoretic displays are called non- emitting displays based on light particle suspensions. They behave as motion of charged particles in a dielectric fluid towards the electrodes with the opposite charge. Electrical and optical properties of electrophoretic displays suspension composition are dependent on the electronic ink that is called E- ink. Thus, key factors in determining image quality depended on electrophoretic particle properties. Enhancing the great image quality for accurate image control and faster response to the voltage applied is dependent on the very small particle size, narrow size distribution and high surface charge of particles. So a lot of research has been done on the modification of particles, surface morphology, surface charge and their stability in media. Therefore, this article reviews the studies of these topics
A Review In Preparation of Electronic Ink for Electrophoretic Displays
Electrophoretic displays attracted a lot of attention recently due to its low cost, low weight, low power consumption and reliability. Based on these characteristics, they are going to replace the conventional paper. Electrophoretic displays are called non- emitting displays based on light particle suspensions. They behave as motion of charged particles in a dielectric fluid towards the electrodes with the opposite charge. Electrical and optical properties of electrophoretic displays suspension composition are dependent on the electronic ink that is called E- ink. Thus, key factors in determining image quality depended on electrophoretic particle properties. Enhancing the great image quality for accurate image control and faster response to the voltage applied is dependent on the very small particle size, narrow size distribution and high surface charge of particles. So a lot of research has been done on the modification of particles, surface morphology, surface charge and their stability in media. Therefore, this article reviews the studies of these topics
Assessing global dietary habits: a comparison of national estimates from the FAO and the Global Dietary Database.
BACKGROUND: Accurate data on dietary habits are crucial for understanding impacts on disease and informing policy priorities. Nation-specific food balance sheets from the United Nations FAO provided the only available global dietary estimates but with uncertain validity. OBJECTIVES: We investigated how FAO estimates compared with nationally representative, individual-based dietary surveys from the Global Dietary Database (GDD) and developed calibration equations to improve the validity of FAO data to estimate dietary intakes. DESIGN: FAO estimates were matched to GDD data for 113 countries across the following 9 major dietary metrics for 30 y of data (1980-2009): fruit, vegetables, beans and legumes, nuts and seeds, whole grains, red and processed meats, fish and seafood, milk, and total energy. Both absolute and percentage differences in FAO and GDD mean estimates were evaluated. Linear regression was used to evaluate whether FAO estimates predicted GDD dietary intakes and whether this prediction varied according to age, sex, region, and time. Calibration equations were developed to adjust FAO estimates to approximate national dietary surveys validated by using randomly split data sets. RESULTS: For most food groups, FAO estimates substantially overestimated individual-based dietary intakes by 74.5% (vegetables) and 270% (whole grains) while underestimating beans and legumes (-50%) and nuts and seeds (-29%) (P < 0.05 for each). In multivariate regressions, these overestimations and underestimations for each dietary factor further varied by age, sex, region, and time (P < 0.001 for each). Split-data set calibration models, which accounted for country-level covariates and other sources of heterogeneity, effectively adjusted FAO estimates to approximate estimates from national survey data (r = 0.47-0.80) with small SEs of prediction (generally 1-5 g/d). CONCLUSIONS: For all food groups and total energy, FAO estimates substantially exceeded or underestimated individual-based national surveys of individual intakes with significant variation depending on age, sex, region, and time. Calibration models effectively adjusted the comprehensive, widely accessible FAO data to facilitate a more-accurate estimation of individual-level dietary intakes nationally and by age and sex.Supported by a grant from the Bill & Melinda Gates Foundation (Global Dietary Habits among Women, Price and Income Elasticities, and Validity of Food Balance Sheets; to LCDG, SH, RM, PS and DM) and the Medical Research Council Epidemiology Unit Core Support (MC_UU_12015/5; to FI).This is the final version of the article. It first appeared from the American Society for Nutrition via http://dx.doi.org/10.3945/ajcn.114.08740
The indirect role of site distribution in high-grade dysplasia in adenomatous colorectal polyps
Background: The appropriate application of Endoscopic modalities for
polypectomy depends on the likelihood that the adenoma in question
harbors invasive cancer. While prior studies have evaluated polyp size
and morphology in assessing the risk of malignancy, in recent decay
some authorities have paid more attention to dysplasia. All in all, the
relative risk of cancer based on polyp distribution in correlation with
dysplasia has not been statistically studied which is done in our
study. Methods and Materials: Between June 2001 and March 2004, the
distribution of 130 adenomatous polyps was compared with synchronous
invasive or in situ cancer. Factors such as Patient age, Patients
gender, location of lesion, size of polyp, histological subtype of
adenoma on biopsy, degree of dysplasia, synchronous cancer, color of
polyp, and number of polyps were included in the data collection.
Results: Multivariate logistic regression test was used to evaluate the
association between malignancy and various clinical variables. It
revealed histological subtype, high grade of dysplasia and size to be
independent predictor of malignancy. However; left-sided location and
histological subtype to be independent risk factor for high-grade
dysplasia. Conclusion: Lesions greater than 1 cm in diameter with
high-grade dysplasia after speleinc flexure should be managed as
presumptive malignancies with segmental colon resection. In
intermediate-risk lesions the physician should decide individually
An explanatory model of depression among female patients in Fars, Kurds, Turks ethnic groups of Iran
Background: Depressive disorder is globally estimated to be as many as one in five visits to primary health care. Approximately more than 50 of depressed women in primary care are not diagnosed. As a part of a major investigation into perceptions of women's depression, this study explored how female patients and their relatives conceptualize patients' conditions in three ethnic groups in Iran (Fars, Kurds and Turks). Methods: Qualitative methods were used for data collection. Depressed women and their relatives were purposively selected from the public psychiatric clinics affiliated to university of medical sciences in the three study cities. Twentyfive depressed women and 14 relatives were interviewed in three ethnic groups. Results: One theme "illness meaning", including three categories: perceived symptoms, label of the illness, and effects of the illness was found through the content analysis. The participants perceived symptoms of illness as somatic and psychological depending on the participant's assumed reason for the onset of the illness. There were most similarities in term used for of the illness in the three ethnic groups. Most of the study participants described the illness in terms of nerve problems/illness, and depression "afsordehgi". The most important effects that depressed women had experienced because of their illness were marital conflict or a guilt feeling originating from their inability to support family. Conclusion: These findings suggest the need to recognize and choose appropriate diagnostic approach for depressed women in the context of Iran
Contributions of mean and shape of blood pressure distribution to worldwide trends and variations in raised blood pressure: a pooled analysis of 1018 population-based measurement studies with 88.6 million participants
Background: Change in the prevalence of raised blood pressure could be due to both shifts in the entire distribution of blood pressure (representing the combined effects of public health interventions and secular trends) and changes in its high-blood-pressure tail (representing successful clinical interventions to control blood pressure in the hypertensive population). Our aim was to quantify the contributions of these two phenomena to the worldwide trends in the prevalence of raised blood pressure.
Methods: We pooled 1,018 population-based studies with blood pressure measurements on 88.6 million participants from 1985 to 2016. We first calculated mean SBP, mean DBP and prevalence of raised blood pressure by sex and 10-year age group from 20-29 years to 70-79 years in each study, taking into account complex survey design and survey sample weights, where relevant. We used a linear mixed effect model to quantify the association between (probit-transformed) prevalence of raised blood pressure and age-group- and sex-specific mean blood pressure. We calculated the contributions of change in mean SBP and DBP, and of change in the prevalence-mean association, to the change in prevalence of raised blood pressure.
Results: In 2005-2016, at the same level of population mean SBP and DBP, men and women in south Asia and in central Asia, Middle East and north Africa would have the highest prevalence of raised blood pressure, and men and women in the high-income Asia Pacific and high-income western regions would have the lowest. In most region-sex-age groups where the prevalence of raised blood pressure declined, one half or more of the decline was due to the decline in mean blood pressure. Where prevalence of raised blood pressure has increased, the change was entirely driven by increasing mean blood pressure, offset partly by the change in the prevalence-mean association.
Conclusions: Change in mean blood pressure is the main driver of the worldwide change in the prevalence of raised blood pressure, but change in the high-blood-pressure tail of the distribution has also contributed to the change in prevalence, especially in older age groups
National and sub-national burden of chronic diseases attributable to lifestyle risk factors in Iran 1990-2013; study protocol
Background: Non-communicable diseases, as the major public health problem, are caused by different risk factors. The main leading lifestyle risk factors for most diseases burden in Iran are unhealthy diet, physical inactivity, and smoking. The aim of this study is to provide data collection and methodology processes for estimating the trends of exposures to the selected lifestyle risk factors and their attributed burden at national and sub-national levels. Methods: Systematic review will be performed through PubMed/MEDLINE, Scopus and ISI/Web of Science as well as Iranian databases such as IranMedex, Irandoc and Scientific Information Database (SID). In addition, hand searching of unpublished data sources will be used to identify relevant population-based studies. The searched studies will be included only if it is reasonably population-based and representative, and exposure data has been reported or could be plausibly obtained from the study. For risk factors with no surveys identified, other sources of potential data will be considered. The target population is healthy Iranian adult population living within Iran from 1990 to 2013. Other data sources include national censuses, national registration systems, and national and sub-national surveys. Spatio-temporal Bayesian hierarchical model and Bayesian multilevel autoregressive model will be used to overcome the problem of data gaps in provinces, and in some age or sex groups or in urban/rural areas. The problem of misaligned areal units will be also addressed in these models. Conclusion: National and sub-national assessment of major lifestyle risk factors such as unhealthy diet, physical inactivity, and smoking is necessary for priority setting and policy making in different regions of Iran
Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015
SummaryBackground The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context. Methods We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors—the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specific DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI). Findings Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each decreased by more than 25%. Global exposure for several occupational risks, high body-mass index (BMI), and drug use increased by more than 25% over the same period. All risks jointly evaluated in 2015 accounted for 57·8% (95% CI 56·6–58·8) of global deaths and 41·2% (39·8–42·8) of DALYs. In 2015, the ten largest contributors to global DALYs among Level 3 risks were high systolic blood pressure (211·8 million [192·7 million to 231·1 million] global DALYs), smoking (148·6 million [134·2 million to 163·1 million]), high fasting plasma glucose (143·1 million [125·1 million to 163·5 million]), high BMI (120·1 million [83·8 million to 158·4 million]), childhood undernutrition (113·3 million [103·9 million to 123·4 million]), ambient particulate matter (103·1 million [90·8 million to 115·1 million]), high total cholesterol (88·7 million [74·6 million to 105·7 million]), household air pollution (85·6 million [66·7 million to 106·1 million]), alcohol use (85·0 million [77·2 million to 93·0 million]), and diets high in sodium (83·0 million [49·3 million to 127·5 million]). From 1990 to 2015, attributable DALYs declined for micronutrient deficiencies, childhood undernutrition, unsafe sanitation and water, and household air pollution; reductions in risk-deleted DALY rates rather than reductions in exposure drove these declines. Rising exposure contributed to notable increases in attributable DALYs from high BMI, high fasting plasma glucose, occupational carcinogens, and drug use. Environmental risks and childhood undernutrition declined steadily with SDI; low physical activity, high BMI, and high fasting plasma glucose increased with SDI. In 119 countries, metabolic risks, such as high BMI and fasting plasma glucose, contributed the most attributable DALYs in 2015. Regionally, smoking still ranked among the leading five risk factors for attributable DALYs in 109 countries; childhood underweight and unsafe sex remained primary drivers of early death and disability in much of sub-Saharan Africa. Interpretation Declines in some key environmental risks have contributed to declines in critical infectious diseases. Some risks appear to be invariant to SDI. Increasing risks, including high BMI, high fasting plasma glucose, drug use, and some occupational exposures, contribute to rising burden from some conditions, but also provide opportunities for intervention. Some highly preventable risks, such as smoking, remain major causes of attributable DALYs, even as exposure is declining. Public policy makers need to pay attention to the risks that are increasingly major contributors to global burden. Funding Bill & Melinda Gates Foundation
Investigating the use of a hybrid plasmonic–photonic nanoresonator for optical trapping using finite-difference time-domain method
We investigate the use of a hybrid nanoresonator comprising a photonic crystal (PhC) cavity coupled to a plasmonic bowtie nanoantenna (BNA) for the optical trapping of nanoparticles in water. Using finite difference time-domain simulations, we show that this structure can confine light to an extremely small volume of ~30,000 nm3 (~30 zl) in the BNA gap whilst maintaining a high quality factor (5400–7700). The optical intensity inside the BNA gap is enhanced by a factor larger than 40 compared to when the BNA is not present above the PhC cavity. Such a device has potential applications in optical manipulation, creating high precision optical traps with an intensity gradient over a distance much smaller than the diffraction limit, potentially allowing objects to be confined to much smaller volumes and making it ideal for optical trapping of Rayleigh particles (particles much smaller than the wavelength of light)
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