267 research outputs found
Al, Pd Elements Deposited on the Surface of Al-Pd-Mn Quasicrystal
Pd element has been deposited on the clean surface of an Al-Pd-Mn quasicrystal by evaporation and using low energy ion scattering (LEIS) technique. The sample was prepared through a combination of sputtering and annealing. Then a Pd monolayer was deposited on the surface and measured the ratio of Al/Pd for clean annealed surface at the room temperature. Drawing the Al/Pd ratio versus time deposition showed a linear behavior, indicating Pd growth is Layer Growth (Frank-Van der-Merwe Growth). Similar experiment for Al has also been done. Results show that growth of Al on the sample is also conform Layer Growth (LG
Low energy ion scattering
Low energy ion scattering (LEIS) is the study of the composition and structure of a surface by the detection of low energy ions with energies ranging from 100 eV to 10 keV elastically scattered off the surface. The extreme sensitivity to the outermost atomic layer makes it as a unique tool for surface analysis. In this paper, concepts of shadowing, blocking, and also polar and azimuthal scans have been described. Surface order and surface atom spacings are revealed by using these concepts and measuring the intensity of backscattered projectiles as a function of the incident and azimuthal angles
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Low vitamin B12 and lipid metabolism: evidence from pre-clinical and clinical studies
Obesity is a worldwide epidemic responsible for 5% of global mortality. The risks of developing other key metabolic disorders like diabetes, hypertension and cardiovascular diseases (CVDs) are increased by obesity, causing a great public health concern. A series of epidemiological studies and animal models have demonstrated a relationship between the importance of vitamin B12 (B12) and various components of metabolic syndrome. High prevalence of low B12 levels has been shown in European (27%) and South Indian (32%) patients with type 2 diabetes (T2D). A longitudinal prospective study in pregnant women has shown that low B12 status could independently predict the development of T2D five years after delivery. Likewise, children born to mothers with low B12 levels may have excess fat accumulation which in turn can result in higher insulin resistance and risk of T2D and/or CVD in adulthood. However, the independent role of B12 on lipid metabolism, a key risk factor for cardiometabolic disorders, has not been explored to a larger extent. In this review, we provide evidence from pre-clinical and clinical studies on the role of low B12 status on lipid metabolism and insights on the possible epigenetic mechanisms including DNA methylation, micro-RNA and histone modifications. Although, there are only a few association studies of B12 on epigenetic mechanisms, novel approaches to understand the functional changes caused by these epigenetic markers are warranted
Deep Learning Model With Adaptive Regularization for EEG-Based Emotion Recognition Using Temporal and Frequency Features
Since EEG signal acquisition is non-invasive and portable, it is convenient to be used for different applications. Recognizing emotions based on Brain-Computer Interface (BCI) is an important active BCI paradigm for recognizing the inner state of persons. There are extensive studies about emotion recognition, most of which heavily rely on staged complex handcrafted EEG feature extraction and classifier design. In this paper, we propose a hybrid multi-input deep model with convolution neural networks (CNNs) and bidirectional Long Short-term Memory (Bi-LSTM). CNNs extract time-invariant features from raw EEG data, and Bi-LSTM allows long-range lateral interactions between features. First, we propose a novel hybrid multi-input deep learning approach for emotion recognition from raw EEG signals. Second, in the first layers, we use two CNNs with small and large filter sizes to extract temporal and frequency features from each raw EEG epoch of 62-channel 2-s and merge with differential entropy of EEG band. Third, we apply the adaptive regularization method over each parallel CNN’s layer to consider the spatial information of EEG acquisition electrodes. The proposed method is evaluated on two public datasets, SEED and DEAP. Our results show that our technique can significantly improve the accuracy in comparison with the baseline where no adaptive regularization techniques are used
Measurement of depth-dose of linear accelerator and simulation by use of Geant4 computer code
AbstractRadiation therapy is an established method of cancer treatment. New technologies in cancer radiotherapy need a more accurate computation of the dose delivered in the radiotherapy treatment plan. This study presents some results of a Geant4-based application for simulation of the absorbed dose distribution given by a medical linear accelerator (LINAC). The LINAC geometry is accurately described in the Monte Carlo code with use of the accelerator manufacturer's specifications. The capability of the software for evaluating the dose distribution has been verified by comparisons with measurements in a water phantom; the comparisons were performed for percentage depth dose (PDD) and profiles for various field sizes and depths, for a 6-MV electron beam. Experimental and calculated dose values were in good agreement both in PDD and in transverse sections of the water phantom
Exploring Dietary Patterns with the Rapid Eating and Activity Assessment for Patients (REAP) Tool in a Dental School Clinic
Background: Dietary pattern assessment by healthcare providers leads to a better understanding of usual intake and evaluation of nutritional status, systemic health, and disease. Interprofessional team members can use such information to provide interventions leading to improved health outcomes. Objective: The aim was to explore the dietary patterns of adults seen in a dental clinic using the Rapid Eating and Activity Assessment for Patients (REAP) tool. Methods: This was a cross-sectional study of data from 220 adult patients (aged 18-89 years) who had a diet evaluation completed in a dental school clinic. Demographic information and REAP responses were obtained from the electronic health record and reported using frequency distributions. Results: The study sample (N=220) was 50.0% male (n= 110). The median (IQR) age and BMI were 56.0 years (IQR=48.2, 66.0) and 28.0 kg/m2 (IQR= 24.3, 32.8 kg/m2), respectively; 73.5% had a BMI considered overweight or obese. Approximately one-third reported usually/sometimes eating sweets more than twice/day (n=74, 35.9%) and drinking more than 16 ounces of SSBs (n=74, 34.1%). Most reported usually/sometimes eating less than 3 servings of whole grains (n=165, 75.0%), 2-3 servings of fruit (n=155, 71.1%), or 3-4 servings of vegetables (n=121, 70.8%) daily. Seventy-two percent (n=156) indicated they were willing to make dietary changes. Conclusion: This study revealed that the dietary patterns of adults seen in a dental school clinic did not align with the Dietary Guidelines for Americans recommendations. Diet assessment is feasible in this setting and may be an important part of interprofessional education
Vertically Aligned Graphene Prepared by Photonic Annealing for Ultrasensitive Biosensors
Graphene exhibits excellent physical, electronic, and chemical properties that are highly desirable for biosensing applications. However, most graphene biosensors are based on graphene lying flat on a substrate and therefore do not utilize its maximum specific surface area for ultrasensitive detection. Herein, we report the novel use of photonic annealing on a flexographically printed graphene–ethyl cellulose composite to produce vertically aligned graphene (VAG) biosensors for ultrasensitive detection of algal toxins in drinking water. These VAG structures, which maximized the specific surface area of graphene, were formed by partial removal of the polymeric binder upon applying intense pulsed light on the printed graphene. A label-free and low-cost VAG biosensor based on a non-faradaic electrochemical impedance spectroscopy technique was fabricated. The biosensor exhibited a limit of detection of 1.2 ng/L for microcystin-LR in local tap water. Such an ultrasensitive VAG biosensor is suitable for low-cost mass production using an integrated roll-to-roll flexographic printing with rapid photonic annealing technique
Incidence of acute myocardial infarction in Islamic Republic of Iran: a study using national registry data in 2012
Population-based data on Myocardial infarction rates in the Islamic Republic of Iran have not been reported on a national or provincial scale. In a cross-sectional study, data were collected on 20 760 new cases Of myocardial infarction (ICD10 codes 121-22) admitted to hospitals and registered by the Iranian Myocardial Infarction Registry in 2012 The crude and age adjusted incidence for the 31 provinces and the whole country were directly calculated per 100 000 people using the WHO standard population. Overall males comprised 72.4% of cases and had a significantly lower Mean age at incidence than women 59.6 (SD 13.3) years versus 65.4 (SD 12.6) years]. The male:female incidence ratio was 2.63. The age-standardized Myocardial infarction incidence rate was 73.3 per 100 000 in country (95% Cl: 72.3%-74.3%) and varied Signifitantly from 24.5 to 152.5 per 100 000 across the I.ji provirites. The Study provides baseline data for monitoring and managing cardiovascular diseases in the country
Effect of intense pulsed light on hydrothermally grown ZnO nanowires
Hydrothermal growth of ZnO nanowires has been of great interest as it allows the use of organic substrates for flexible electronics applications. However, there are drawbacks on the growth technique as it is known to introduce defects in the nanowires. In this work, the use of intense pulsed light on hydrothermally grown ZnO nanowires on polyimide substrate was performed to enhance the physical and electronic properties of the nanomaterials. Such photonic annealing technique offers a rapid and effective improvement in material properties and importantly it is suitable for use on a wide variety of organic substrates, which are vital for flexible electronics
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