187 research outputs found
Strong interfacial exchange field in the graphene/EuS heterostructure
Exploiting 2D materials for spintronic applications can potentially realize
next-generation devices featuring low-power consumption and quantum operation
capability. The magnetic exchange field (MEF) induced by an adjacent magnetic
insulator enables efficient control of local spin generation and spin
modulation in 2D devices without compromising the delicate material structures.
Using graphene as a prototypical 2D system, we demonstrate that its coupling to
the model magnetic insulator (EuS) produces a substantial MEF (> 14 T) with
potential to reach hundreds of Tesla, which leads to orders-of-magnitude
enhancement in the spin signal originated from Zeeman spin-Hall effect.
Furthermore, the new ferromagnetic ground state of Dirac electrons resulting
from the strong MEF may give rise to quantized spin-polarized edge transport.
The MEF effect shown in our graphene/EuS devices therefore provides a key
functionality for future spin logic and memory devices based on emerging 2D
materials in classical and quantum information processing
Quantum computing in power systems
Electric power systems provide the backbone of modern industrial societies. Enabling scalable grid analytics is the keystone to successfully operating large transmission and distribution systems. However, today’s power systems are suffering from ever-increasing computational burdens in sustaining the expanding communities and deep integration of renewable energy resources, as well as managing huge volumes of data accordingly. These unprecedented challenges call for transformative analytics to support the resilient operations of power systems. Recently, the explosive growth of quantum computing techniques has ignited new hopes of revolutionizing power system computations. Quantum computing harnesses quantum mechanisms to solve traditionally intractable computational problems, which may lead to ultra-scalable and efficient power grid analytics. This paper reviews the newly emerging application of quantum computing techniques in power systems. We present a comprehensive overview of existing quantum-engineered power analytics from different operation perspectives, including static analysis, transient analysis, stochastic analysis, optimization, stability, and control. We thoroughly discuss the related quantum algorithms, their benefits and limitations, hardware implementations, and recommended practices. We also review the quantum networking techniques to ensure secure communication of power systems in the quantum era. Finally, we discuss challenges and future research directions. This paper will hopefully stimulate increasing attention to the development of quantum-engineered smart grids
Evolution of carbapenem resistance in Acinetobacter baumannii: An 18-year longitudinal study from a medical center in northern Taiwan
BackgroundCarbapenem-resistant Acinetobacter baumannii has emerged as an important cause of nosocomial infections with high morbidity and mortality. The carbapenemases, especially class D carbapenem-hydrolyzing oxacillinases (CHDLs), play an important role, but the relationship between their prevalence trend and carbapenem resistance remains unclear.Materials and methodsBetween 1995 and 2012, we collected 667 isolates of A. baumannii from a single medical center in northern Taiwan. Pulsed-field gel electrophoresis (PFGE) was used to determine clonality. Antimicrobial susceptibility was determined. Carbapenemase genes and associated genetic structures were detected by polymerase chain reaction.ResultsIsolates were heterogeneous on PFGE. Susceptibility to carbapenem decreased steadily over the study period from 88.1% (2001–2003) to <25% (2010–2012), whereas the isolates remained susceptible to colistin (nearly 100%) and partially susceptible to tigecycline (80%). Starting in 2001, isolates carrying the ISAba1-blaOXA-51-like allele were consistently identified. Isolates containing the transposons Tn2006 or Tn2008 first appeared in 2007 with increasing carriage rates from 17.5% (2007–2009) to 50.0% (2010–2012). The IS1008-ΔISAba3-blaOXA-58-like, blaOXA-72 and metallo-β-lactamase genes were detected only sporadically. Isolates carrying CHDL genes were resistant to multiple drugs, including carbapenem, but remained susceptible to colistin (100.0%).ConclusionIncreased carbapenem resistance in A. baumannii may be caused by the increased prevalence of isolates containing the ISAba1-blaOXA-51-like allele and the transposons Tn2006 and Tn2008
The Dipyridamole Added to Dual Antiplatelet Therapy in Cerebral Infarction After First Acute Myocardial Infarction: A Nationwide, Case-Control Study
Background and Purpose: No previous study has compared the impact of dipyridamole-based triple antiplatelet therapy on secondary stroke prevention and long-term outcomes to that of dual antiplatelet therapy (DAPT) in patients with acute myocardial infarction (AMI) and previous stroke. This study aimed to evaluate the impact of dipyridamole added to DAPT on stroke prevention and long-term outcomes in patients with cerebral infarction after first AMI.Methods: This nationwide, case-control study included 75,789 patients with cerebral infarction after first AMI. A 1:4 propensity score matching ratio was adopted based on multiple variables. Finally, the data of 4,468 patients included in the DAPT group and 1,117 patients included in the Dipyridamole-DAPT group were analyzed. Primary outcome was overall survival. Secondary outcomes were cumulative event rate of recurrent MI or stroke, and cumulative intracerebral hemorrhage (ICH) and gastrointestinal bleeding rate.Results: Long-term survival rate was comparable between the two groups (log-rank P = 0.1117), regardless of sex analyses. However, after first year, DAPT subgroup revealed better survival over DAPT-dipyridamole subgroup (log-rank P = 0.0188). In age subgroup analysis, a lower survival rate was detected in younger patients from the Dipyridamole-DAPT group after first year (log-rank P = 0.0151), but no survival difference for older patients. No benefit of Dipyridamole-DAPT was detected for patients after AMI, regardless of the myocardial infarction type. DAPT was superior to Dipyridamole-DAPT in patients who underwent percutaneous coronary intervention (PCI) (log-rank P = 0.0153) and ST elevation myocardial infarction after first year (log-rank P = 0.0019). Dipyridamole-DAPT did not reduce cumulative event rate of recurrent MI or stroke in patients after AMI. Moreover, Dipyridamole-DAPT increased the cumulative ICH rate (log-rank P = 0.0026), but did not affect the cumulative event rate of gastrointestinal bleeding. In Cox analysis, dipyridamole did not improve long-term survival.Conclusions: This nationwide study showed that Dipyridamole-DAPT, compared with DAPT, did not improve long-term survival in patients with stroke after AMI, and was related to poor outcomes after 1 year. Dipyridamole-DAPT did not reduce recurrent rate of MI or stroke, but increased the ICH rate without impacting the incidence of gastrointestinal bleeding
Chronic Kidney Disease, But Not Diabetes, Can Predict 30-Day Outcomes in Patients with ST-Elevation Myocardial Infarction after Primary Percutaneous Coronary Intervention: A Single-Center Experience
Background: Patients with acute coronary syndrome and impaired renal function have been shown to have high mortality. However, there is scarce literature to date addressing the impact of diabetes mellitus (DM) and renal function on clinical outcomes of ST elevation myocardial infarction (STEMI) in Taiwan. Method: This study enrolled 512 STEMI patients who received primary percutaneous coronary intervention. Patients were divided into 4 groups including group 1: patients without DM or CKD (nDM-nCKD); group 2: patients with DM but without CKD (DM-nCKD); group 3: patients with CKD but without DM (nDM-CKD); group 4: patients with DM and CKD (DM-CKD). Patients were also classified into four groups based on their estimated glomerular filtration rates (eGFR): stage 1 (eGFR 90 ml/min/1.73 m 2 , n = 163), stage 2 (eGFR = 89-60 ml/min/1.73 m 2 , n = 171), stage 3 (eGFR = 59-30 ml/min/1.73 m 2 , n = 136), and stage 4 (eGFR < 30 ml/min/1.73 m 2 , n = 42). The complication rates, length of hospital stay, and 30-day outcomes were analyzed. Results: The patients in both the nDM-CKD group and DM-CKD group had higher incidences of hypotension, intra-aortic balloon counterpulsation use, and respiratory failure (p < 0.005). They had significantly longer hospital stay and 30-day mortality rates (p < 0.001). The patients with CKD stage 3 and 4 had longer hospital stay and higher 30-day mortality rates (p < 0.001). However, DM was not an independent factor on the length of hospital stay and 30-day mortality rates. Conclusions: STEMI patients with impaired renal function, but not DM, had significantly longer hospital stay and higher 30-day mortality rates
The IPIN 2019 Indoor Localisation Competition—Description and Results
IPIN 2019 Competition, sixth in a series of IPIN competitions, was held at the CNR Research Area of Pisa (IT), integrated into the program of the IPIN 2019 Conference. It included two on-site real-time Tracks and three off-site Tracks. The four Tracks presented in this paper were set in the same environment, made of two buildings close together for a total usable area of 1000 m 2 outdoors and and 6000 m 2 indoors over three floors, with a total path length exceeding 500 m. IPIN competitions, based on the EvAAL framework, have aimed at comparing the accuracy performance of personal positioning systems in fair and realistic conditions: past editions of the competition were carried in big conference settings, university campuses and a shopping mall. Positioning accuracy is computed while the person carrying the system under test walks at normal walking speed, uses lifts and goes up and down stairs or briefly stops at given points. Results presented here are a showcase of state-of-the-art systems tested side by side in real-world settings as part of the on-site real-time competition Tracks. Results for off-site Tracks allow a detailed and reproducible comparison of the most recent positioning and tracking algorithms in the same environment as the on-site Tracks
Unprecedented random lasing in 2D organolead halide single-crystalline perovskite microrods
Three-dimensional organic–inorganic hybrid halide perovskites have been demonstrated as great materials for applications in optoelectronics and photonics. However, their inherent instabilities in the presence of moisture, light, and heat may hinder their commercialization. Alternatively, emerging two-dimensional (2D) organic–inorganic hybrid perovskites have recently attracted increasing attention owing to their great environmental stability and inherent natural quantum-well structure. In this work, we have synthesized a high-quality long-chain organic diammonium spacer assisted 2D hybrid perovskite FA-(N-MPDA)PbBr4 (FA = formamidinium and N-MPDA = N-methylpropane-1,3-diammonium) by the slow evaporation at constant temperature method. The millimeter-sized single-crystalline microrods demonstrate low threshold random lasing behavior at room temperature. The single-crystalline 2D hybrid perovskite random laser achieved a very narrow linewidth (∼0.1 nm) with a low threshold (∼0.5 μJ cm−2) and a high quality factor (∼5350). Furthermore, the 2D hybrid microrod laser shows stable lasing emission with no measurable degradation after at least 2 h under continuous illumination, which substantially proves the stability of 2D perovskites. Our results demonstrate the promise of 2D organic–inorganic microrod-shaped perovskites and provide an important step toward the realization of high-performance optoelectronic devices
Large expert-curated database for benchmarking document similarity detection in biomedical literature search
Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
Genome-wide association study of lung adenocarcinoma in East Asia and comparison with a European population.
Lung adenocarcinoma is the most common type of lung cancer. Known risk variants explain only a small fraction of lung adenocarcinoma heritability. Here, we conducted a two-stage genome-wide association study of lung adenocarcinoma of East Asian ancestry (21,658 cases and 150,676 controls; 54.5% never-smokers) and identified 12 novel susceptibility variants, bringing the total number to 28 at 25 independent loci. Transcriptome-wide association analyses together with colocalization studies using a Taiwanese lung expression quantitative trait loci dataset (n = 115) identified novel candidate genes, including FADS1 at 11q12 and ELF5 at 11p13. In a multi-ancestry meta-analysis of East Asian and European studies, four loci were identified at 2p11, 4q32, 16q23, and 18q12. At the same time, most of our findings in East Asian populations showed no evidence of association in European populations. In our studies drawn from East Asian populations, a polygenic risk score based on the 25 loci had a stronger association in never-smokers vs. individuals with a history of smoking (Pinteraction = 0.0058). These findings provide new insights into the etiology of lung adenocarcinoma in individuals from East Asian populations, which could be important in developing translational applications
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