Thermal infrared emission reveals the Dirac point movement in biased graphene

Graphene is a 2-dimensional material with high carrier mobility and thermal conductivity, suitable for high-speed electronics. Conduction and valence bands touch at the Dirac point. The absorptivity of single-layer graphene is 2.3%, nearly independent of wavelength. Here we investigate the thermal radiation from biased graphene transistors. We find that the emission spectrum of single-layer graphene follows that of a grey body with constant emissivity (1.6 \pm 0.8)%. Most importantly, we can extract the temperature distribution in the ambipolar graphene channel, as confirmed by Stokes/anti-Stokes measurements. The biased graphene exhibits a temperature maximum whose location can be controlled by the gate voltage. We show that this peak in temperature reveals the spatial location of the minimum in carrier density, i.e. the Dirac point.Comment: Accepted in principle at Nature Nanotechnolog

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

Multiple Correspondence Analysis is a Useful Tool to Visualize Complex Categorical Correlated Data

ABSTRACT Objectives We sought to identify the most expensive hospitalized individuals in the Canadian province of Saskatchewan in fiscal year 2012/13, and determine the primary cause of their high use of health services. Our aim was to identify health problems that can be prevented or better managed in a non-hospital health care setting. Comorbid conditions are an important and confounding covariate in this population and so we used multiple correspondence analysis (MCA) to investigate the association of these conditions with each other and the most responsible diagnosis for each hospitalization. MCA is a multivariable descriptive statistical technique that displays the relationship between categorical variables in 2-dimensional graphical form. Approach We identified the most expensive 5% of people hospitalized between 01APR2012 and 31MAR2013. Hospital costs accounted for the majority of costs, but physician, drug, long-term care, and home care costs were added. Comorbid conditions in any of the 25 hospital diagnostic fields were identified and grouped into categories based upon ICD-10-CA subcategories. For example, category 1 was ICD-10-CA codes F10-F19: Mental and behavioural disorders due to psychoactive drug use, while category 2 was ICD-10-CA codes F20-F29: Schizophrenia, schizotypal, and delusional disorders. SAS™ v9.3 was used to conduct MCA and generate graphs displaying the correlation between each comorbid condition category, where the distance of each dot from the other represents the strength of the association between the disease categories (i.e., diseases that are correlated cluster together.) The frequency of each category of comorbid condition was represented by the size of the dots on the graph (e.g., the more people with the disease, the larger the dot.) Categories of comorbid conditions were redefined based upon data findings and clinical expertise. Results Three patient groups emerged as being amenable to intervention and thus cost savings, specifically (1) individuals of advanced age who are no longer able to live at home and are hospitalized while waiting for a bed in a long-term care facility, (2) individuals with a mental health and/or addiction problem, and (3) individuals who experienced medical harm during their time in hospital. Conclusion MCA is a valuable graphical tool that is easy to learn and, in conjunction with other statistical techniques, can be used to elucidate the relationship between complex correlated categorical variables

Additional file 1: of The effects of patient education programs on medication use among asthma and COPD patients: a propensity score matching with a difference-in-difference regression approach

There is an online appendix uploaded in pdf format with a file name ofHSR_Online_appendix. It presents the full results from our empirical analysis including a brief description of databases used in this paper. (PDF 856 kb

ARTYKUŁ ORYGINALNYZwiązek pomiędzy zwrotem załamka T a klinicznymi i angiograficznymi parametrami u w ostrej fazie zawału serca

Background: Restoration of a positive T-wave in the chronic stage of myocardial infarction (MI) is usually seen in patients with a non-Q-wave (non-transmural) MI, where a viable tissue is present. The causes and significance of a positive T-wave in the early phase of acute MI are not clear. Aim: To investigate angiographic and clinical characteristics of patients with a positive T-wave in the early stage of acute MI. Methods: We evaluated the clinical and angiographic data in relation to T-wave polarity in 188 patients with acute MI. Coronary risk factors, pre-infarction angina, CK-MB level, left ventricular ejection fraction and angiographic findings were analysed. Death, cardiogenic shock, ventricular tachycardia/fibrillation and high-degree atrioventricular block were regarded as in-hospital complications. All electrocardiograms were divided into two groups, according to the shape of the T-wave, as exhibiting a positive T-wave or negative T-wave. Results: A positive T-wave was present in 30 (15.9%) patients. None of the patients with a positive T-wave had three-vessel disease compared with 21.5% of patients with a negative T-wave (pWstęp: Powrót dodatnich załamków T po przebyciu ostrej fazy zawału serca (MI) obserwuje się zwykle u chorych, którzy przebyli MI bez załamka Q i mają zachowaną żywotność mięśnia sercowego. Mechanizmy prowadzące do występowania dodatnich załamków T już we wczesnej fazie MI i znaczenie tego zjawiska nie zostały jeszcze dokładnie wyjaśnione. Cel: Ocena parametrów angiograficznych i klinicznych u chorych z dodatnim załamkiem T stwierdzanym w ostrej fazie MI. Metodyka: Grupę badaną stanowiło 188 chorych z ostrym MI. Analizowano czynniki ryzyka choroby wieńcowej, obecność bólów wieńcowych przed MI, stężenie CK-MB, frakcję wyrzutową lewej komory i wyniki koronarografii. Podczas obserwacji wewnątrzszpitalnej oceniano występowanie następujących powikłań sercowo-naczyniowych: zgon, wstrząs kardiogenny, częstoskurcz komorowy, migotanie komór lub zaawansowany blok przedsionkowo-komorowy. Chorzy zostali podzieleni na dwie grupy w zależności od dodatniego lub ujemnego wychylenia załamka T. Wyniki: Dodatnie załamki T w ostrej fazie MI stwierdzono u 30 (15.9%) chorych. Chorobę trzech naczyń stwierdzono u 21.5% chorych z ujemnym załamkiem T i u żadnego chorego z grupy z dodatnim załamkiem T (

Comparison of physical examination and MRI for the diagnosis of intraarticular knee pathologies: analysis of 968 knees

BACKGROUND: It is very important to evaluate intraarticular knee pathologies carefully to make a proper diagnosis. The most important diagnostic tools are history-taking, physical examination including special knee tests, and radiology including magnetic resonance imaging. The purpose of this study is to make a comparison between physical examination and magnetic resonance imaging for intraarticular knee pathologies before knee arthroscopy which is accepted as the gold standard for these types of pathologies