Flexible transistor‐structured memory (FTSM) has attracted great attention for its important role in flexible electronics. For nonvolatile information storage, FTSMs with floating‐gate, charge‐trap, ...and ferroelectric mechanisms have been developed. By introducing an optical sensory module, FTSM can be operated by optical inputs to function as an optical memory transistor. As a special type of FTSM, transistor‐structured artificial synapse emulates important functions of a biological synapse to mimic brain‐inspired memory behaviors and nervous signal transmissions. This work reviews the recent development of the above mentioned FTSMs, with a focus on working mechanism and materials, and flexibility.
Flexible transistor‐structured memory (FTSM) has attracted great attention for its important role in flexible electronics. For nonvolatile information storage, various FTSMs with different mechanisms and functions have been developed. This paper reviews the recent development of five kinds of FTSMs, with a focus on working mechanism and materials, and flexibility.
An analysis of national cardiovascular data showed that median door-to-balloon times for primary PCI declined from 83 minutes in 2005 to 67 minutes in 2009, whereas in-hospital mortality remained ...unchanged during this period.
Primary percutaneous coronary intervention (PCI) is currently the preferred treatment for acute ST-segment elevation myocardial infarction. Previous observational studies have shown a strong association between prompt performance of primary PCI, as assessed in terms of the door-to-balloon time (the interval from the patient's arrival at the hospital to inflation of the balloon to restore flow), and reduced mortality.
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On the basis of these data, current joint clinical practice guidelines of the American College of Cardiology and the American Heart Association (ACC–AHA) endorse a door-to-balloon time of 90 minutes or less as the goal, giving it a Class I (highest . . .
Summary Background Despite the importance of ST-segment elevation myocardial infarction (STEMI) in China, no nationally representative studies have characterised the clinical profiles, management, ...and outcomes of this cardiac event during the past decade. We aimed to assess trends in characteristics, treatment, and outcomes for patients with STEMI in China between 2001 and 2011. Methods In a retrospective analysis of hospital records, we used a two-stage random sampling design to create a nationally representative sample of patients in China admitted to hospital for STEMI in 3 years (2001, 2006, and 2011). In the first stage, we used a simple random-sampling procedure stratified by economic–geographical region to generate a list of participating hospitals. In the second stage we obtained case data for rates of STEMI, treatments, and baseline characteristics from patients attending each sampled hospital with a systematic sampling approach. We weighted our findings to estimate nationally representative rates and assess changes from 2001 to 2011. This study is registered with ClinicalTrials.gov , number NCT01624883. Findings We sampled 175 hospitals (162 participated in the study) and 18 631 acute myocardial infarction admissions, of which 13 815 were STEMI admissions. 12 264 patients were included in analysis of treatments, procedures, and tests, and 11 986 were included in analysis of in-hospital outcomes. Between 2001 and 2011, estimated national rates of hospital admission for STEMI per 100 000 people increased (from 3·5 in 2001, to 7·9 in 2006, to 15·4 in 2011; ptrend <0·0001) and the prevalence of risk factors—including smoking, hypertension, diabetes, and dyslipidaemia—increased. We noted significant increases in use of aspirin within 24 h (79·7% 95% CI 77·9–81·5 in 2001 vs 91·2% 90·5–91·8 in 2011, ptrend <0·0001) and clopidogrel (1·5% 95% CI 1·0–2·1 in 2001 vs 82·1% 81·1–83·0 in 2011, ptrend <0·0001) in patients without documented contraindications. Despite an increase in the use of primary percutaneous coronary intervention (10·6% 95% CI 8·6–12·6 in 2001 vs 28·1% 26·6–29·7 in 2011, ptrend <0·0001), the proportion of patients who did not receive reperfusion did not significantly change (45·3% 95% CI 42·1–48·5 in 2001 vs 44·8% 43·1–46·5 in 2011, ptrend =0·69). The median length of hospital stay decreased from 12 days (IQR 7–18) in 2001 to 10 days (6–14) in 2011 (ptrend <0·0001). Adjusted in-hospital mortality did not significantly change between 2001 and 2011 (odds ratio 0·82, 95% CI 0·62–1·10, ptrend =0·07). Interpretation During the past decade in China, hospital admissions for STEMI have risen; in these patients, comorbidities and the intensity of testing and treatment have increased. Quality of care has improved for some treatments, but important gaps persist and in-hospital mortality has not decreased. National efforts are needed to improve the care and outcomes for patients with STEMI in China. Funding National Health and Family Planning Commission of China.
Artificial synapses (ASs) are electronic devices emulating important functions of biological synapses, which are essential building blocks of artificial neuromorphic networks for brain‐inspired ...computing. A human brain consists of several quadrillion synapses for information storage and processing, and massively parallel computation. Neuromorphic systems require ASs to mimic biological synaptic functions, such as paired‐pulse facilitation, short‐term potentiation, long‐term potentiation, spatiotemporally‐correlated signal processing, and spike‐timing‐dependent plasticity, etc. Feature size and energy consumption of ASs need to be minimized for high‐density energy‐efficient integration. This work reviews recent progress on ASs. First, synaptic plasticity and functional emulation are introduced, and then synaptic electronic devices for neuromorphic computing systems are discussed. Recent advances in flexible artificial synapses for artificial sensory nerves are also briefly introduced. Finally, challenges and opportunities in the field are discussed.
Artificial synapses emulate important functions of biological synapses. They are essential building blocks of neuromorphic networks for brain‐inspired computing. To realize high‐density energy‐efficient integration, feature size and energy consumption of single devices need to be minimized. Following a general introduction to synaptic plasticity, artificial synapses based on various materials, structures and mechanisms are discussed.
Abstract Background Various national campaigns launched in recent years have focused on young women with acute myocardial infarctions (AMIs). Contemporary longitudinal data about sex differences in ...clinical characteristics, hospitalization rates, length of stay (LOS), and mortality have not been examined. Objectives This study sought to determine sex differences in clinical characteristics, hospitalization rates, LOS, and in-hospital mortality by age group and race among young patients with AMIs using a large national dataset of U.S. hospital discharges. Methods Using the National Inpatient Sample, clinical characteristics, AMI hospitalization rates, LOS, and in-hospital mortality were compared for patients with AMI across ages 30 to 54 years, dividing them into 5-year subgroups from 2001 to 2010, using survey data analysis techniques. Results A total of 230,684 hospitalizations were identified with principal discharge diagnoses of AMI in 30- to 54-year-old patients from Nationwide Inpatient Sample data, representing an estimated 1,129,949 hospitalizations in the United States from 2001 to 2010. No statistically significant declines in AMI hospitalization rates were observed in the age groups <55 years or stratified by sex. Prevalence of comorbidities was higher in women and increased among both sexes through the study period. Women had longer LOS and higher in-hospital mortality than men across all age groups. However, observed in-hospital mortality declined significantly for women from 2001 to 2010 (from 3.3% to 2.3%, relative change 30.5%; p for trend < 0.0001) but not for men (from 2% to 1.8%, relative change 8.6%; p for trend = 0.60). Conclusions AMI hospitalization rates for young people have not declined over the past decade. Young women with AMIs have more comorbidity, longer LOS, and higher in-hospital mortality than young men, although their mortality rates are decreasing.
With the rapid development of the intelligent video surveillance (IVS), person re-identification, which is a difficult yet unavoidable problem in video surveillance, has received increasing attention ...in recent years. That is because computer capacity has shown remarkable progress and the task of person re-identification plays a critical role in video surveillance systems. In short, person re-identification aims to find an individual again that has been observed over different cameras. It has been reported that KISS metric learning has obtained the state of the art performance for person re-identification on the VIPeR dataset . However, given a small size training set, the estimation to the inverse of a covariance matrix is not stable and thus the resulting performance can be poor. In this paper, we present regularized smoothing KISS metric learning (RS-KISS) by seamlessly integrating smoothing and regularization techniques for robustly estimating covariance matrices. RS-KISS is superior to KISS, because RS-KISS can enlarge the underestimated small eigenvalues and can reduce the overestimated large eigenvalues of the estimated covariance matrix in an effective way. By providing additional data, we can obtain a more robust model by RS-KISS. However, retraining RS-KISS on all the available examples in a straightforward way is time consuming, so we introduce incremental learning to RS-KISS. We thoroughly conduct experiments on the VIPeR dataset and verify that 1) RS-KISS completely beats all available results for person re-identification and 2) incremental RS-KISS performs as well as RS-KISS but reduces the computational cost significantly.
IMPORTANCE Little is known about the risk of individuals who are released from correctional facilities, a time where their may be discontinuity in care. OBJECTIVE To study the risk for ...hospitalizations among former inmates soon after their release from correctional facilities. DESIGN Retrospective cohort study. PARTICIPANTS Data from Medicare administrative claims for 110 419 fee-for-service beneficiaries who were released from a correctional facility from 2002 through 2010 and controls matched by age, sex, race, Medicare status, and residential zip code. MAIN OUTCOMES AND MEASURES Hospitalization rates and specifically those for ambulatory care–sensitive conditions 7, 30, and 90 days after release. RESULTS Of 110 419 released inmates, 1559 individuals (1.4%) were hospitalized within 7 days after release; 4285 individuals (3.9%) within 30 days; and 9196 (8.3%) within 90 days. The odds of hospitalization was higher for released inmates compared with those of matched controls (within 7 days: odds ratio OR, 2.5 95% CI, 2.3-2.8; within 30 days: OR, 2.1 95% CI, 2.0-2.2; and within 90 days: OR, 1.8 95% CI, 1.7-1.9). Compared with matched controls, former inmates were more likely to be hospitalized for ambulatory care–sensitive conditions (within 7 days: OR, 1.7 95% CI, 1.4-2.1; within 30 days: OR, 1.6 95% CI, 1.5-1.8; and within 90 days: OR, 1.6 95% CI, 1.5-1.7). CONCLUSIONS AND RELEVANCE About 1 in 70 former inmates are hospitalized for an acute condition within 7 days of release, and 1 in 12 by 90 days, a rate much higher than in the general population.
Summary Background Recent reductions in average door-to-balloon (D2B) times have not been associated with decreases in mortality at the population level. We investigated this seemingly paradoxical ...finding by assessing components of this association at the individual and population levels simultaneously. We postulated that the changing population of patients undergoing primary percutaneous coronary intervention (pPCI) contributed to secular trends toward an increasing mortality risk, despite consistently decreased mortality in individual patients with shorter D2B times. Methods This was a retrospective study of ST-elevation myocardial infarction (STEMI) patients who underwent pPCI between Jan 1, 2005, and Dec 31, 2011, in the National Cardiovascular Data Registry (NCDR) CathPCI Registry. We looked for catheterisation laboratory visits associated with STEMI. We excluded patients not undergoing pPCI, transfer patients for pPCI, patients with D2B times less than 15 min or more than 3 h, and patients at hospitals that did not consistently report data across the study period. We assessed in-hospital mortality in the entire cohort and 6-month mortality in elderly patients aged 65 years or older matched to data from the Centers for Medicare and Medicaid Services. We built multilevel models to assess the relation between D2B time and in-hospital and 6-month mortality, including both individual and population-level components of this association after adjusting for patient and procedural factors. Findings 423 hospitals reported data on 150 116 procedures with a 55% increase in the number of patients undergoing pPCI at these facilities over time, as well as many changes in patient and procedural factors. Annual D2B times decreased significantly from a median of 86 min (IQR 65–109) in 2005 to 63 min (IQR 47–80) in 2011 (p<0·0001) with a concurrent rise in risk-adjusted in-hospital mortality (from 4·7% to 5·3%; p=0·06) and risk-adjusted 6-month mortality (from 12·9% to 14·4%; p=0·001). In multilevel models, shorter patient-specific D2B times were consistently associated at the individual level with lower in-hospital mortality (adjusted OR for each 10 min decrease 0·92; 95% CI 0·91–0·93; p<0·0001) and 6-month mortality (adjusted OR for each 10 min decrease, 0·94; 95% CI 0·93–0·95; p<0·0001). By contrast, risk-adjusted in-hospital and 6-month mortality at the population level, independent of patient-specific D2B times, rose in the growing and changing population of patients undergoing pPCI during the study period. Interpretation Shorter patient-specific D2B times were consistently associated with lower mortality over time, whereas secular trends suggest increased mortality risk in the growing and changing pPCI population. The absence of association of annual D2B time and changes in mortality at the population level should not be interpreted as an indication of its individual-level relation in patients with STEMI undergoing primary PCI. Funding National Heart, Lung, and Blood Institute.
Distributed denial of service (DDoS) attack is an attempt to make an online service unavailable by overwhelming it with traffic from multiple sources. Therefore, it is necessary to propose an ...effective method to detect DDoS attack from massive data traffics. However, the existing schemes have some limitations, including that supervised learning methods, need large numbers of labeled data and unsupervised learning algorithms have relatively low detection rate and high false positive rate. In order to tackle these issues, this paper presents a semi-supervised weighted k-means detection method. Specifically, we firstly present a Hadoop-based hybrid feature selection algorithm to find the most effective feature sets and propose an improved density-based initial cluster centers selection algorithm to solve the problem of outliers and local optimal. Then, we provide the Semi-supervised K-means algorithm using hybrid feature selection (SKM-HFS) to detect attacks. Finally, we exploit DARPA DDoS dataset, CAIDA "DDoS attack 2007" dataset, CICIDS "DDoS attack 2017" dataset and real-world dataset to carry out the verification experiment. The experiment results have demonstrated that the proposed method outperforms the benchmark in the respect of detection performance and technique for order preference by similarity to an ideal solution (TOPSIS) evaluation factor.
SUMMARY
Since electromagnetic (EM) fields diffuse more smoothly to greater depth, it physically makes sense to apply fine discretization to model structure at near surface with an increasingly ...coarser grid both in horizontal and vertical directions as the depth increases for the numerical solution of EM fields. For finite-difference magnetotelluric (MT) forward modelling on regular staggered grids, this can lead to difficulties in discretizing the curl–curl equation governing the EM diffusion in the earth at regions, where the grid resolution changes. In this paper, we propose an efficient algebraic multi-resolution sampling (MRS) method for MT forward modelling. In this method, we do not require the generation of physical subgrids and merely subsample the field components. The coefficient matrix for the subsampled components can be obtained by matrix multiplication based on the initial linear system of equations and field interpolation. To guarantee divergence-free current during the iterative solution process at low frequencies, which is considered crucial for the development of efficient iterative solvers, our forward modelling is based a regularization equation obtained by augmenting the curl–curl equation with an equivalent scaled grad–div operator for electrical fields (explicitly enforcing the divergence-free condition). The correctness of our algebraic MRS algorithm is examined based on a layered model. Its stability and efficiency is exploited by comparing our results with the forward modelling on unsampled staggered grids for the Dublin Test Model 1 (DTM1) and a complex model with realistic topography, indicating a time reduction of about 42–82 per cent.
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